Techniques

Adversaries may stage collected data in a central location or directory on the local system prior to Exfiltration. Data may be kept in separate files or combined into one file through techniques such as Archive Collected Data. Interactive command shells may be used, and common functionality within cmd and bash may be used to copy data into a staging location.

Adversaries may also stage collected data in various available formats/locations of a system, including local storage databases/repositories or the Windows Registry.[1]

Adversaries may target user email on local systems to collect sensitive information. Files containing email data can be acquired from a user’s local system, such as Outlook storage or cache files.

Outlook stores data locally in offline data files with an extension of .ost. Outlook 2010 and later supports .ost file sizes up to 50GB, while earlier versions of Outlook support up to 20GB.[1] IMAP accounts in Outlook 2013 (and earlier) and POP accounts use Outlook Data Files (.pst) as opposed to .ost, whereas IMAP accounts in Outlook 2016 (and later) use .ost files. Both types of Outlook data files are typically stored in `C:\Users\\Documents\Outlook Files` or `C:\Users\\AppData\Local\Microsoft\Outlook`.[2]

Adversaries may attempt to find local system groups and permission settings. The knowledge of local system permission groups can help adversaries determine which groups exist and which users belong to a particular group. Adversaries may use this information to determine which users have elevated permissions, such as the users found within the local administrators group.

Commands such as net localgroup of the Net utility, dscl . -list /Groups on macOS, and groups on Linux can list local groups.

Adversaries may enumerate local drives, disks, and/or volumes and their attributes like total or free space and volume serial number. This can be done to prepare for ransomware-related encryption, to perform Lateral Movement, or as a precursor to Direct Volume Access.

On ESXi systems, adversaries may use Hypervisor CLI commands such as `esxcli` to list storage connected to the host as well as `.vmdk` files.[1][2]

On Windows systems, adversaries can use `wmic logicaldisk get` to find information about local network drives. They can also use `Get-PSDrive` in PowerShell to retrieve drives and may additionally use Windows API functions such as `GetDriveType`.[3][4]

Linux has commands such as `parted`, `lsblk`, `fdisk`, `lshw`, and `df` that can list information about disk partitions such as size, type, file system types, and free space. The command `diskutil` on MacOS can be used to list disks while `system_profiler SPStorageDataType` can additionally show information such as a volume’s mount path, file system, and the type of drive in the system.

Infrastructure as a Service (IaaS) cloud providers also have commands for storage discovery such as `describe volume` in AWS, `gcloud compute disks list` in GCP, and `az disk list` in Azure.[5][6][7]

Adversaries may track a device’s physical location through use of standard operating system APIs via malicious or exploited applications on the compromised device.

On Android, applications holding the `ACCESS_COAURSE_LOCATION` or `ACCESS_FINE_LOCATION` permissions provide access to the device’s physical location. On Android 10 and up, declaration of the `ACCESS_BACKGROUND_LOCATION` permission in an application’s manifest will allow applications to request location access even when the application is running in the background.[1] Some adversaries have utilized integration of Baidu map services to retrieve geographical location once the location access permissions had been obtained.[2][3]

On iOS, applications must include the `NSLocationWhenInUseUsageDescription`, `NSLocationAlwaysAndWhenInUseUsageDescription`, and/or `NSLocationAlwaysUsageDescription` keys in their `Info.plist` file depending on the extent of requested access to location information.[4] On iOS 8.0 and up, applications call `requestWhenInUseAuthorization()` to request access to location information when the application is in use or `requestAlwaysAuthorization()` to request access to location information regardless of whether the application is in use. With elevated privileges, an adversary may be able to access location data without explicit user consent with the `com.apple.locationd.preauthorized` entitlement key.[5]

An adversary with physical access to a mobile device may seek to bypass the device’s lockscreen. Several methods exist to accomplish this, including:

* Biometric spoofing: If biometric authentication is used, an adversary could attempt to spoof a mobile device’s biometric authentication mechanism. Both iOS and Android partly mitigate this attack by requiring the device’s passcode rather than biometrics to unlock the device after every device restart, and after a set or random amount of time.[1][2] * Unlock code bypass: An adversary could attempt to brute-force or otherwise guess the lockscreen passcode (typically a PIN or password), including physically observing (“shoulder surfing”) the device owner’s use of the lockscreen passcode. Mobile OS vendors partly mitigate this by implementing incremental backoff timers after a set number of failed unlock attempts, as well as a configurable full device wipe after several failed unlock attempts. * Vulnerability exploit: Techniques have been periodically demonstrated that exploit mobile devices to bypass the lockscreen. The vulnerabilities are generally patched by the device or OS vendor once disclosed.[3][4]

Adversaries may enumerate system and service logs to find useful data. These logs may highlight various types of valuable insights for an adversary, such as user authentication records (Account Discovery), security or vulnerable software (Software Discovery), or hosts within a compromised network (Remote System Discovery).

Host binaries may be leveraged to collect system logs. Examples include using `wevtutil.exe` or PowerShell on Windows to access and/or export security event information.[1][2] In cloud environments, adversaries may leverage utilities such as the Azure VM Agent’s `CollectGuestLogs.exe` to collect security logs from cloud hosted infrastructure.[3]

Adversaries may also target centralized logging infrastructure such as SIEMs. Logs may also be bulk exported and sent to adversary-controlled infrastructure for offline analysis.

In addition to gaining a better understanding of the environment, adversaries may also monitor logs in real time to track incident response procedures. This may allow them to adjust their techniques in order to maintain persistence or evade defenses.[4]

Adversaries may use a Login Hook to establish persistence executed upon user logon. A login hook is a plist file that points to a specific script to execute with root privileges upon user logon. The plist file is located in the /Library/Preferences/com.apple.loginwindow.plist file and can be modified using the defaults command-line utility. This behavior is the same for logout hooks where a script can be executed upon user logout. All hooks require administrator permissions to modify or create hooks.[1][2]

Adversaries can add or insert a path to a malicious script in the com.apple.loginwindow.plist file, using the LoginHook or LogoutHook key-value pair. The malicious script is executed upon the next user login. If a login hook already exists, adversaries can add additional commands to an existing login hook. There can be only one login and logout hook on a system at a time.[3][4]

**Note:** Login hooks were deprecated in 10.11 version of macOS in favor of Launch Daemon and Launch Agent

Adversaries may add login items to execute upon user login to gain persistence or escalate privileges. Login items are applications, documents, folders, or server connections that are automatically launched when a user logs in.[1] Login items can be added via a shared file list or Service Management Framework.[2] Shared file list login items can be set using scripting languages such as AppleScript, whereas the Service Management Framework uses the API call SMLoginItemSetEnabled.

Login items installed using the Service Management Framework leverage launchd, are not visible in the System Preferences, and can only be removed by the application that created them.[2][3] Login items created using a shared file list are visible in System Preferences, can hide the application when it launches, and are executed through LaunchServices, not launchd, to open applications, documents, or URLs without using Finder.[4] Users and applications use login items to configure their user environment to launch commonly used services or applications, such as email, chat, and music applications.

Adversaries can utilize AppleScript and Native API calls to create a login item to spawn malicious executables.[5] Prior to version 10.5 on macOS, adversaries can add login items by using AppleScript to send an Apple events to the “System Events” process, which has an AppleScript dictionary for manipulating login items.[6] Adversaries can use a command such as tell application “System Events” to make login item at end with properties /path/to/executable.[7][8][9] This command adds the path of the malicious executable to the login item file list located in ~/Library/Application Support/com.apple.backgroundtaskmanagementagent/backgrounditems.btm.[7] Adversaries can also use login items to launch executables that can be used to control the victim system remotely or as a means to gain privilege escalation by prompting for user credentials.[10][11][12]

Adversaries may use Windows logon scripts automatically executed at logon initialization to establish persistence. Windows allows logon scripts to be run whenever a specific user or group of users log into a system.[1] This is done via adding a path to a script to the HKCU\Environment\UserInitMprLogonScript Registry key.[2]

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.

Adversaries may attempt to disrupt essential components or systems to prevent owner and operator from delivering products or services. [1] [2] [3]

Adversaries may leverage malware to delete or encrypt critical data on HMIs, workstations, or databases.

In the 2021 Colonial Pipeline ransomware incident, pipeline operations were temporally halted on May 7th and were not fully restarted until May 12th. [4]

Adversaries may seek to achieve a sustained loss of control or a runaway condition in which operators cannot issue any commands even if the malicious interference has subsided. [1] [2] [3]

The German Federal Office for Information Security (BSI) reported a targeted attack on a steel mill in its 2014 IT Security Report.[4] These targeted attacks affected industrial operations and resulted in breakdowns of control system components and even entire installations. As a result of these breakdowns, massive impact resulted in damage and unsafe conditions from the uncontrolled shutdown of a blast furnace.

Adversaries may cause loss of productivity and revenue through disruption and even damage to the availability and integrity of control system operations, devices, and related processes. This technique may manifest as a direct effect of an ICS-targeting attack or tangentially, due to an IT-targeting attack against non-segregated environments.

In cases where these operations or services are brought to a halt, the loss of productivity may eventually present an impact for the end-users or consumers of products and services. The disrupted supply-chain may result in supply shortages and increased prices, among other consequences.

A ransomware attack on an Australian beverage company resulted in the shutdown of some manufacturing sites, including precautionary halts to protect key systems. [1] The company announced the potential for temporary shortages of their products following the attack. [1] [2]

In the 2021 Colonial Pipeline ransomware incident, the pipeline was unable to transport approximately 2.5 million barrels of fuel per day to the East Coast. [3]

Adversaries may compromise protective system functions designed to prevent the effects of faults and abnormal conditions. This can result in equipment damage, prolonged process disruptions and hazards to personnel.

Many faults and abnormal conditions in process control happen too quickly for a human operator to react to. Speed is critical in correcting these conditions to limit serious impacts such as Loss of Control and Property Damage.

Adversaries may target and disable protective system functions as a prerequisite to subsequent attack execution or to allow for future faults and abnormal conditions to go unchecked. Detection of a Loss of Protection by operators can result in the shutdown of a process due to strict policies regarding protection systems. This can cause a Loss of Productivity and Revenue and may meet the technical goals of adversaries seeking to cause process disruptions.

Adversaries may compromise safety system functions designed to maintain safe operation of a process when unacceptable or dangerous conditions occur. Safety systems are often composed of the same elements as control systems but have the sole purpose of ensuring the process fails in a predetermined safe manner.

Many unsafe conditions in process control happen too quickly for a human operator to react to. Speed is critical in correcting these conditions to limit serious impacts such as Loss of Control and Property Damage.

Adversaries may target and disable safety system functions as a prerequisite to subsequent attack execution or to allow for future unsafe conditionals to go unchecked. Detection of a Loss of Safety by operators can result in the shutdown of a process due to strict policies regarding safety systems. This can cause a Loss of Productivity and Revenue and may meet the technical goals of adversaries seeking to cause process disruptions.

Adversaries may cause a sustained or permanent loss of view where the ICS equipment will require local, hands-on operator intervention; for instance, a restart or manual operation. By causing a sustained reporting or visibility loss, the adversary can effectively hide the present state of operations. This loss of view can occur without affecting the physical processes themselves. [1] [2] [3]

Adversaries may abuse Lua commands and scripts for execution. Lua is a cross-platform scripting and programming language primarily designed for embedded use in applications. Lua can be executed on the command-line (through the stand-alone lua interpreter), via scripts (.lua), or from Lua-embedded programs (through the struct lua_State).[1][2]

Lua scripts may be executed by adversaries for malicious purposes. Adversaries may incorporate, abuse, or replace existing Lua interpreters to allow for malicious Lua command execution at runtime.[3][4][5][6]

Adversaries may abuse mmc.exe to proxy execution of malicious .msc files. Microsoft Management Console (MMC) is a binary that may be signed by Microsoft and is used in several ways in either its GUI or in a command prompt.[1][2] MMC can be used to create, open, and save custom consoles that contain administrative tools created by Microsoft, called snap-ins. These snap-ins may be used to manage Windows systems locally or remotely. MMC can also be used to open Microsoft created .msc files to manage system configuration.[3]

For example, mmc C:\Users\foo\admintools.msc /a will open a custom, saved console msc file in author mode.[1] Another common example is mmc gpedit.msc, which will open the Group Policy Editor application window.

Adversaries may use MMC commands to perform malicious tasks. For example, mmc wbadmin.msc delete catalog -quiet deletes the backup catalog on the system (i.e. Inhibit System Recovery) without prompts to the user (Note: wbadmin.msc may only be present by default on Windows Server operating systems).[4][5]

Adversaries may also abuse MMC to execute malicious .msc files. For example, adversaries may first create a malicious registry Class Identifier (CLSID) subkey, which uniquely identifies a Component Object Model class object.[6] Then, adversaries may create custom consoles with the “Link to Web Address” snap-in that is linked to the malicious CLSID subkey.[7] Once the .msc file is saved, adversaries may invoke the malicious CLSID payload with the following command: mmc.exe -Embedding C:\path\to\test.msc.[8]

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.[1]

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.[1][2] 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.[3]

Adversaries may communicate using application layer protocols associated with electronic mail delivery to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Protocols such as SMTP/S, POP3/S, and IMAP that carry electronic mail may be very common in environments. Packets produced from these protocols may have many fields and headers in which data can be concealed. Data could also be concealed within the email messages themselves. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.[1]

Adversaries may make new tokens and impersonate users to escalate privileges and bypass access controls. For example, if an adversary has a username and password but the user is not logged onto the system the adversary can then create a logon session for the user using the `LogonUser` function.[1] The function will return a copy of the new session's access token and the adversary can use `SetThreadToken` to assign the token to a thread.

This behavior is distinct from Token Impersonation/Theft in that this refers to creating a new user token instead of stealing or duplicating an existing one.

An adversary may rely upon a user copying and pasting code in order to gain execution. Users may be subjected to social engineering to get them to copy and paste code directly into a Command and Scripting Interpreter. One such strategy is "ClickFix," in which adversaries present users with seemingly helpful solutions—such as prompts to fix errors or complete CAPTCHAs—that instead instruct the user to copy and paste malicious code.

Malicious websites, such as those used in Drive-by Compromise, may present fake error messages or CAPTCHA prompts that instruct users to open a terminal or the Windows Run Dialog box and execute an arbitrary command. These commands may be obfuscated using encoding or other techniques to conceal malicious intent. Once executed, the adversary will typically be able to establish a foothold on the victim's machine.[1][2][3][4]

Adversaries may also leverage phishing emails for this purpose. When a user attempts to open an attachment, they may be presented with a fake error and offered a malicious command to paste as a solution, consistent with the "ClickFix" strategy.[5][6]

Tricking a user into executing a command themselves may help to bypass email filtering, browser sandboxing, or other mitigations designed to protect users against malicious downloaded files.

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. Adversaries may use several types of files that require a user to execute them, including .doc, .pdf, .xls, .rtf, .scr, .exe, .lnk, .pif, .cpl, .reg, and .iso.[1]

Adversaries may employ various forms of Masquerading and Obfuscated Files or Information 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.[2]

While Malicious File 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.

Adversaries may rely on a user running a malicious image to facilitate execution. Amazon Web Services (AWS) Amazon Machine Images (AMIs), Google Cloud Platform (GCP) Images, and Azure Images as well as popular container runtimes such as Docker can be backdoored. Backdoored images may be uploaded to a public repository via Upload Malware, and users may then download and deploy an instance or container from the image without realizing the image is malicious, thus bypassing techniques that specifically achieve Initial Access. This can lead to the execution of malicious code, such as code that executes cryptocurrency mining, in the instance or container.[1]

Adversaries may also name images a certain way to increase the chance of users mistakenly deploying an instance or container from the image (ex: Match Legitimate Resource Name or Location).[2]

Adversaries may rely on a user installing a malicious library to facilitate execution. Threat actors may Upload Malware to package managers such as NPM and PyPi, as well as to public code repositories such as GitHub. User may install libraries without realizing they are malicious, thus bypassing techniques that specifically achieve Initial Access. This can lead to the execution of malicious code, such as code that establishes persistence, steals data, or mines cryptocurrency.[1][2]

In some cases, threat actors may compromise and backdoor existing popular libraries (i.e., Compromise Software Dependencies and Development Tools). Alternatively, they may create entirely new packages and leverage behaviors such as typosquatting to encourage users to install them.