Enterprise techniques

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

Adversaries may do this using a Command and Scripting Interpreter, such as cmd as well as a Network Device CLI, which have functionality to interact with the file system to gather information.[1] Adversaries may also use Automated Collection on the local system.

Adversaries may search network shares on computers they have compromised to find files of interest. Sensitive data can be collected from remote systems via shared network drives (host shared directory, network file server, etc.) that are accessible from the current system prior to Exfiltration. Interactive command shells may be in use, and common functionality within cmd may be used to gather information.

Adversaries may search connected removable media on computers they have compromised to find files of interest. Sensitive data can be collected from any removable media (optical disk drive, USB memory, etc.) connected to the compromised system prior to Exfiltration. Interactive command shells may be in use, and common functionality within cmd may be used to gather information.

Some adversaries may also use Automated Collection on removable media.

Adversaries may employ various means to detect and avoid debuggers. Debuggers are typically used by defenders to trace and/or analyze the execution of potential malware payloads.[1]

Debugger evasion may include changing behaviors based on the results of the checks for the presence of artifacts indicative of a debugged environment. Similar to Virtualization/Sandbox Evasion, if the adversary detects a debugger, they may alter their malware to disengage from the victim or conceal the core functions of the implant. They may also search for debugger artifacts before dropping secondary or additional payloads.

Specific checks will vary based on the target and/or adversary. On Windows, this may involve Native API function calls such as IsDebuggerPresent() and NtQueryInformationProcess(), or manually checking the BeingDebugged flag of the Process Environment Block (PEB). On Linux, this may involve querying `/proc/self/status` for the `TracerPID` field, which indicates whether or not the process is being traced by dynamic analysis tools.[2][3] Other checks for debugging artifacts may also seek to enumerate hardware breakpoints, interrupt assembly opcodes, time checks, or measurements if exceptions are raised in the current process (assuming a present debugger would “swallow” or handle the potential error).[4][5][6]

Malware may also leverage Structured Exception Handling (SEH) to detect debuggers by throwing an exception and detecting whether the process is suspended. SEH handles both hardware and software expectations, providing control over the exceptions including support for debugging. If a debugger is present, the program’s control will be transferred to the debugger, and the execution of the code will be suspended. If the debugger is not present, control will be transferred to the SEH handler, which will automatically handle the exception and allow the program’s execution to continue.[7]

Adversaries may use the information learned from these debugger checks during automated discovery to shape follow-on behaviors. Debuggers can also be evaded by detaching the process or flooding debug logs with meaningless data via messages produced by looping Native API function calls such as OutputDebugStringW().[8][9]

Adversaries may modify visual content available internally or externally to an enterprise network, thus affecting the integrity of the original content. Reasons for Defacement include delivering messaging, intimidation, or claiming (possibly false) credit for an intrusion. Disturbing or offensive images may be used as a part of Defacement in order to cause user discomfort, or to pressure compliance with accompanying messages.

Adversaries may employ various time-based methods to evade detection and analysis. These techniques often exploit system clocks, delays, or timing mechanisms to obscure malicious activity, blend in with benign activity, and avoid scrutiny. Adversaries can perform this behavior within virtualization/sandbox environments or natively on host systems.

Adversaries may utilize programmatic `sleep` commands or native system scheduling functionality, for example Scheduled Task/Job. Benign commands or other operations may also be used to delay malware execution or ensure prior commands have had time to execute properly. Loops or otherwise needless repetitions of commands, such as `ping`, may be used to delay malware execution and potentially exceed time thresholds of automated analysis environments.[1][2] Another variation, commonly referred to as API hammering, involves making various calls to Native API functions in order to delay execution (while also potentially overloading analysis environments with junk data).[3][4]

Adversaries may use Obfuscated Files or Information to hide artifacts of an intrusion from analysis. They may require separate mechanisms to decode or deobfuscate that information depending on how they intend to use it. Methods for doing that include built-in functionality of malware or by using utilities present on the system.

One such example is the use of certutil to decode a remote access tool portable executable file that has been hidden inside a certificate file.[1] Another example is using the Windows copy /b or type command to reassemble binary fragments into a malicious payload.[2][3]

Sometimes a user's action may be required to open it for deobfuscation or decryption as part of User Execution. The user may also be required to input a password to open a password protected compressed/encrypted file that was provided by the adversary.[4]

Adversaries may deploy a container into an environment to facilitate execution or evade defenses. In some cases, adversaries may deploy a new container to execute processes associated with a particular image or deployment, such as processes that execute or download malware. In others, an adversary may deploy a new container configured without network rules, user limitations, etc. to bypass existing defenses within the environment. In Kubernetes environments, an adversary may attempt to deploy a privileged or vulnerable container into a specific node in order to Escape to Host and access other containers running on the node. [1]

Containers can be deployed by various means, such as via Docker's create and start APIs or via a web application such as the Kubernetes dashboard or Kubeflow. [2][3][4] In Kubernetes environments, containers may be deployed through workloads such as ReplicaSets or DaemonSets, which can allow containers to be deployed across multiple nodes.[5] Adversaries may deploy containers based on retrieved or built malicious images or from benign images that download and execute malicious payloads at runtime.[6]

Adversaries may build capabilities that can be used during targeting. Rather than purchasing, freely downloading, or stealing capabilities, adversaries may develop their own capabilities in-house. This is the process of identifying development requirements and building solutions such as malware, exploits, and self-signed certificates. Adversaries may develop capabilities to support their operations throughout numerous phases of the adversary lifecycle.[1][2][3][4]

As with legitimate development efforts, different skill sets may be required for developing capabilities. The skills needed may be located in-house, or may need to be contracted out. Use of a contractor may be considered an extension of that adversary's development capabilities, provided the adversary plays a role in shaping requirements and maintains a degree of exclusivity to the capability.

Adversaries may attempt to enumerate local device drivers on a victim host. Information about device drivers may highlight various insights that shape follow-on behaviors, such as the function/purpose of the host, present security tools (i.e. Security Software Discovery) or other defenses (e.g., Virtualization/Sandbox Evasion), as well as potential exploitable vulnerabilities (e.g., Exploitation for Privilege Escalation).

Many OS utilities may provide information about local device drivers, such as `driverquery.exe` and the `EnumDeviceDrivers()` API function on Windows.[1][2] Information about device drivers (as well as associated services, i.e., System Service Discovery) may also be available in the Registry.[3]

On Linux/macOS, device drivers (in the form of kernel modules) may be visible within `/dev` or using utilities such as `lsmod` and `modinfo`.[4][5][6]

Adversaries may directly access a volume to bypass file access controls and file system monitoring. Windows allows programs to have direct access to logical volumes. Programs with direct access may read and write files directly from the drive by analyzing file system data structures. This technique may bypass Windows file access controls as well as file system monitoring tools.[1]

Utilities, such as `NinjaCopy`, exist to perform these actions in PowerShell.[2] Adversaries may also use built-in or third-party utilities (such as `vssadmin`, `wbadmin`, and esentutl) to create shadow copies or backups of data from system volumes.[3]

Adversaries may disable or modify host-based or network firewalls to impair defensive mechanisms and enable further action. Once an adversary has gathered sufficient privileges, they can tamper with firewall services, policies, or rule sets to remove restrictions on inbound or outbound traffic. For example, this may include turning off firewall profiles, altering existing rules to permit previously blocked ports or protocols, or adding new rules that create covert communication paths (e.g., adding a new firewall rule for a well-known protocol (such as RDP) using a non-traditional and potentially less securitized port.[1]

Adversaries may disable or modify firewalls using different behaviors, depending on the platform. For example, in ESXi, firewall rules may be modified directly via the esxcli (e.g., via esxcli network firewall set) or via the vCenter user interface.[2][3]

Adversaries may disable, degrade, or tamper with security tools or applications (e.g., endpoint detection and response (EDR) tools, intrusion detection systems (IDS), antivirus, logging agents, sensors, etc.) to impair or reduce visibility of defensive capabilities. This may include stopping specific services, killing processes, modifying or deleting tool configuration files and Registry keys, or preventing tools from updating. This may also include impairing defenses more broadly by disrupting preventative, detection, and response mechanisms across host, network, and cloud environments.[1]

In addition to directly targeting tools, adversaries may block or manipulate indicators and telemetry used for detection. This includes maliciously disabling or redirecting sensors such as Event Tracing for Windows (ETW), modifying event log configurations (e.g., redirecting Security logs), or interfering with logging pipelines and forwarding mechanisms (e.g., SIEM ingestion).[2][3]

More advanced techniques include leveraging legitimate drivers or debugging mechanisms to render tools non-functional, bypassing anti-tampering protections, and targeting specific defenses such as Sysmon or cloud monitoring agents. Adversaries may also disrupt broader defensive operations, including update mechanisms, logging infrastructure (e.g., syslog), or event aggregation, further degrading an organization’s ability to detect and respond to malicious activity.[4]

Adversaries may wipe or corrupt raw disk data on specific systems or in large numbers in a network to interrupt availability to system and network resources. With direct write access to a disk, adversaries may attempt to overwrite portions of disk data. Adversaries may opt to wipe arbitrary portions of disk data and/or wipe disk structures like the master boot record (MBR). A complete wipe of all disk sectors may be attempted.

To maximize impact on the target organization in operations where network-wide availability interruption is the goal, malware used for wiping disks may have worm-like features to propagate across a network by leveraging additional techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.[1]

On network devices, adversaries may wipe configuration files and other data from the device using Network Device CLI commands such as `erase`.[2]

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.[1] 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, Pass the Ticket, and Kerberoasting.[2][3] Domain trusts can be enumerated using the `DSEnumerateDomainTrusts()` Win32 API call, .NET methods, and LDAP.[3] The Windows utility Nltest is known to be used by adversaries to enumerate domain trusts.[4]

Adversaries may modify the configuration settings of a domain or identity tenant to evade defenses and/or escalate privileges in centrally managed environments. Such services provide a centralized means of managing identity resources such as devices and accounts, and often include configuration settings that may apply between domains or tenants such as trust relationships, identity syncing, or identity federation.

Modifications to domain or tenant settings may include altering domain Group Policy Objects (GPOs) in Microsoft Active Directory (AD) or changing trust settings for domains, including federation trusts relationships between domains or tenants.

With sufficient permissions, adversaries can modify domain or tenant policy settings. Since configuration settings for these services apply to a large number of identity resources, there are a great number of potential attacks malicious outcomes that can stem from this abuse. Examples of such abuse include:

* modifying GPOs to push a malicious Scheduled Task to computers throughout the domain environment[1][2][3] * modifying domain trusts to include an adversary-controlled domain, allowing adversaries to forge access tokens that will subsequently be accepted by victim domain resources[4] * changing configuration settings within the AD environment to implement a Rogue Domain Controller. * adding new, adversary-controlled federated identity providers to identity tenants, allowing adversaries to authenticate as any user managed by the victim tenant [5]

Adversaries may temporarily modify domain or tenant policy, carry out a malicious action(s), and then revert the change to remove suspicious indicators.

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 or even network protocols that can be abused to enable Adversary-in-the-Middle or Network Sniffing.[1] For example, PowerShell 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 while running malicious scripts that may have otherwise been detected.[2][3][4]

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.[5][6] On Windows systems, adversaries may downgrade the boot manager to a vulnerable version that bypasses Secure Boot, granting the ability to disable various operating system security mechanisms.[7]

Adversaries may gain access to a system through a user visiting a website over the normal course of browsing. Multiple ways of delivering exploit code to a browser exist (i.e., Drive-by Target), including:

* A legitimate website is compromised, allowing adversaries to inject malicious code * 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) * Built-in web application interfaces that allow user-controllable content are leveraged for the insertion of malicious scripts or iFrames (e.g., cross-site scripting)

Browser push notifications may also be abused by adversaries and leveraged for malicious code injection via User Execution. By clicking "allow" on browser push notifications, users may be granting a website permission to run JavaScript code on their browser.[1][2][3]

Often the website used by an adversary is one visited by a specific community, such as government, a particular industry, or a particular 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.[4]

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, notifications, 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, the adversary will gain 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, 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 dynamically establish connections to command and control infrastructure to evade common detections and remediations. This may be achieved by using malware that shares a common algorithm with the infrastructure the adversary uses to receive the malware's communications. These calculations can be used to dynamically adjust parameters such as the domain name, IP address, or port number the malware uses for command and control.

Adversaries may use dynamic resolution for the purpose of Fallback Channels. When contact is lost with the primary command and control server malware may employ dynamic resolution as a means to reestablishing command and control.[1][2][3]

Adversaries may abuse ESXi administration services to execute commands on guest machines hosted within an ESXi virtual environment. Persistent background services on ESXi-hosted VMs, such as the VMware Tools Daemon Service, allow for remote management from the ESXi server. The tools daemon service runs as `vmtoolsd.exe` on Windows guest operating systems, `vmware-tools-daemon` on macOS, and `vmtoolsd ` on Linux.[1]

Adversaries may leverage a variety of tools to execute commands on ESXi-hosted VMs – for example, by using the vSphere Web Services SDK to programmatically execute commands and scripts via APIs such as `StartProgramInGuest`, `ListProcessesInGuest`, `ListFileInGuest`, and `InitiateFileTransferFromGuest`.[2][3] This may enable follow-on behaviors on the guest VMs, such as File and Directory Discovery, Data from Local System, or OS Credential Dumping.

Adversaries may flood targeted email addresses with an overwhelming volume of messages. This may bury legitimate emails in a flood of spam and disrupt business operations.[1][2]

An adversary may accomplish email bombing by leveraging an automated bot to register a targeted address for e-mail lists that do not validate new signups, such as online newsletters. The result can be a wave of thousands of e-mails that effectively overloads the victim’s inbox.[2][3]

By sending hundreds or thousands of e-mails in quick succession, adversaries may successfully divert attention away from and bury legitimate messages including security alerts, daily business processes like help desk tickets and client correspondence, or ongoing scams.[3] This behavior can also be used as a tool of harassment.[2]

This behavior may be a precursor for Spearphishing Voice. For example, an adversary may email bomb a target and then follow up with a phone call to fraudulently offer assistance. This social engineering may lead to the use of Remote Access Software to steal credentials, deploy ransomware, conduct Financial Theft[1], or engage in other malicious activity.[4]

Adversaries may target user email to collect sensitive information. Emails may contain sensitive data, including trade secrets or personal information, that can prove valuable to adversaries. Emails may also contain details of ongoing incident response operations, which may allow adversaries to adjust their techniques in order to maintain persistence or evade defenses.[1][2] Adversaries can collect or forward email from mail servers or clients.

Adversaries may employ an encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Despite the use of a secure algorithm, these implementations may be vulnerable to reverse engineering if secret keys are encoded and/or generated within malware samples/configuration files.

Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users. Endpoint DoS can be performed by exhausting the system resources those services are hosted on or exploiting the system to cause a persistent crash condition. Example services include websites, email services, DNS, and web-based applications. Adversaries have been observed conducting DoS attacks for political purposes[1] and to support other malicious activities, including distraction[2], hacktivism, and extortion.[3]

An Endpoint DoS denies the availability of a service without saturating the network used to provide access to the service. Adversaries can target various layers of the application stack that is hosted on the system used to provide the service. These layers include the Operating Systems (OS), server applications such as web servers, DNS servers, databases, and the (typically web-based) applications that sit on top of them. Attacking each layer requires different techniques that take advantage of bottlenecks that are unique to the respective components. A DoS attack may be generated by a single system or multiple systems spread across the internet, which is commonly referred to as a distributed DoS (DDoS).

To perform DoS attacks against endpoint resources, several aspects apply to multiple methods, including IP address spoofing and botnets.

Adversaries may use the original IP address of an attacking system, or spoof the source IP address to make the attack traffic more difficult to trace back to the attacking system or to enable reflection. This can increase the difficulty defenders have in defending against the attack by reducing or eliminating the effectiveness of filtering by the source address on network defense devices.

Botnets are commonly used to conduct DDoS 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 DDoS, so many systems are used to generate requests that each one only needs to send out a small amount of traffic to produce enough volume to exhaust the target's resources. In such circumstances, distinguishing DDoS traffic from legitimate clients becomes exceedingly difficult. Botnets have been used in some of the most high-profile DDoS attacks, such as the 2012 series of incidents that targeted major US banks.[4]

In cases where traffic manipulation is used, there may be points in the global network (such as high traffic gateway routers) where packets can be altered and cause legitimate clients to execute code that directs network packets toward a target in high volume. This type of capability was previously used for the purposes of web censorship where client HTTP traffic was modified to include a reference to JavaScript that generated the DDoS code to overwhelm target web servers.[5]

For attacks attempting to saturate the providing network, see Network Denial of Service.

Adversaries may break out of a container or virtualized environment to gain access to the underlying host. This can allow an adversary access to other containerized or virtualized resources from the host level or to the host itself. In principle, containerized / virtualized resources should provide a clear separation of application functionality and be isolated from the host environment.[1]

There are multiple ways an adversary may escape from a container to a host environment. Examples include creating a container configured to mount the host’s filesystem using the bind parameter, which allows the adversary to drop payloads and execute control utilities such as cron on the host; utilizing a privileged container to run commands or load a malicious kernel module on the underlying host; or abusing system calls such as `unshare` and `keyctl` to escalate privileges and steal secrets.[2][3][4][5][6][7]

Additionally, an adversary may be able to exploit a compromised container with a mounted container management socket, such as `docker.sock`, to break out of the container via a Container Administration Command.[5] Adversaries may also escape via Exploitation for Privilege Escalation, such as exploiting vulnerabilities in global symbolic links in order to access the root directory of a host machine.[8]

In ESXi environments, an adversary may exploit a vulnerability in order to escape from a virtual machine into the hypervisor.[9]

Gaining access to the host may provide the adversary with the opportunity to achieve follow-on objectives, such as establishing persistence, moving laterally within the environment, accessing other containers or virtual machines running on the host, or setting up a command and control channel on the host.