Class: Trojan
A malicious program designed to electronically spy on the user’s activities (intercept keyboard input, take screenshots, capture a list of active applications, etc.). The collected information is sent to the cybercriminal by various means, including email, FTP, and HTTP (by sending data in a request).Read more
Platform: Win32
Win32 is an API on Windows NT-based operating systems (Windows XP, Windows 7, etc.) that supports execution of 32-bit applications. One of the most widespread programming platforms in the world.Family: Trojan.Win32.Reconyc
No family descriptionExamples
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89BD90C879CF24BDD7319D736CBC6195
702CF9603441EED7B83AEAB653E18F22
Tactics and Techniques: Mitre*
Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the “run keys” in the Registry or startup folder will cause the program referenced to be executed when a user logs in.(Citation: Microsoft Run Key) These programs will be executed under the context of the user and will have the account’s associated permissions level.
The following run keys are created by default on Windows systems:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnce
Run keys may exist under multiple hives.(Citation: Microsoft Wow6432Node 2018)(Citation: Malwarebytes Wow6432Node 2016) The HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnceEx is also available but is not created by default on Windows Vista and newer. Registry run key entries can reference programs directly or list them as a dependency.(Citation: Microsoft Run Key) For example, it is possible to load a DLL at logon using a “Depend” key with RunOnceEx: reg add HKLMSOFTWAREMicrosoftWindowsCurrentVersionRunOnceEx 001Depend /v 1 /d "C:tempevil[.]dll" (Citation: Oddvar Moe RunOnceEx Mar 2018)
Placing a program within a startup folder will also cause that program to execute when a user logs in. There is a startup folder location for individual user accounts as well as a system-wide startup folder that will be checked regardless of which user account logs in. The startup folder path for the current user is C:Users\[Username]AppDataRoamingMicrosoftWindowsStart MenuProgramsStartup. The startup folder path for all users is C:ProgramDataMicrosoftWindowsStart MenuProgramsStartUp.
The following Registry keys can be used to set startup folder items for persistence:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
The following Registry keys can control automatic startup of services during boot:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServices
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServices
Using policy settings to specify startup programs creates corresponding values in either of two Registry keys:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
Programs listed in the load value of the registry key HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows run automatically for the currently logged-on user.
By default, the multistring BootExecute value of the registry key HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession Manager is set to autocheck autochk *. This value causes Windows, at startup, to check the file-system integrity of the hard disks if the system has been shut down abnormally. Adversaries can add other programs or processes to this registry value which will automatically launch at boot.
Adversaries can use these configuration locations to execute malware, such as remote access tools, to maintain persistence through system reboots. Adversaries may also use Masquerading to make the Registry entries look as if they are associated with legitimate programs.
Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the “run keys” in the Registry or startup folder will cause the program referenced to be executed when a user logs in.(Citation: Microsoft Run Key) These programs will be executed under the context of the user and will have the account’s associated permissions level.
The following run keys are created by default on Windows systems:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnce
Run keys may exist under multiple hives.(Citation: Microsoft Wow6432Node 2018)(Citation: Malwarebytes Wow6432Node 2016) The HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnceEx is also available but is not created by default on Windows Vista and newer. Registry run key entries can reference programs directly or list them as a dependency.(Citation: Microsoft Run Key) For example, it is possible to load a DLL at logon using a “Depend” key with RunOnceEx: reg add HKLMSOFTWAREMicrosoftWindowsCurrentVersionRunOnceEx 001Depend /v 1 /d "C:tempevil[.]dll" (Citation: Oddvar Moe RunOnceEx Mar 2018)
Placing a program within a startup folder will also cause that program to execute when a user logs in. There is a startup folder location for individual user accounts as well as a system-wide startup folder that will be checked regardless of which user account logs in. The startup folder path for the current user is C:Users\[Username]AppDataRoamingMicrosoftWindowsStart MenuProgramsStartup. The startup folder path for all users is C:ProgramDataMicrosoftWindowsStart MenuProgramsStartUp.
The following Registry keys can be used to set startup folder items for persistence:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
The following Registry keys can control automatic startup of services during boot:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServices
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServices
Using policy settings to specify startup programs creates corresponding values in either of two Registry keys:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
Programs listed in the load value of the registry key HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows run automatically for the currently logged-on user.
By default, the multistring BootExecute value of the registry key HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession Manager is set to autocheck autochk *. This value causes Windows, at startup, to check the file-system integrity of the hard disks if the system has been shut down abnormally. Adversaries can add other programs or processes to this registry value which will automatically launch at boot.
Adversaries can use these configuration locations to execute malware, such as remote access tools, to maintain persistence through system reboots. Adversaries may also use Masquerading to make the Registry entries look as if they are associated with legitimate programs.
Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the “run keys” in the Registry or startup folder will cause the program referenced to be executed when a user logs in.(Citation: Microsoft Run Key) These programs will be executed under the context of the user and will have the account’s associated permissions level.
The following run keys are created by default on Windows systems:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnce
Run keys may exist under multiple hives.(Citation: Microsoft Wow6432Node 2018)(Citation: Malwarebytes Wow6432Node 2016) The HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnceEx is also available but is not created by default on Windows Vista and newer. Registry run key entries can reference programs directly or list them as a dependency.(Citation: Microsoft Run Key) For example, it is possible to load a DLL at logon using a “Depend” key with RunOnceEx: reg add HKLMSOFTWAREMicrosoftWindowsCurrentVersionRunOnceEx 001Depend /v 1 /d "C:tempevil[.]dll" (Citation: Oddvar Moe RunOnceEx Mar 2018)
Placing a program within a startup folder will also cause that program to execute when a user logs in. There is a startup folder location for individual user accounts as well as a system-wide startup folder that will be checked regardless of which user account logs in. The startup folder path for the current user is C:Users\[Username]AppDataRoamingMicrosoftWindowsStart MenuProgramsStartup. The startup folder path for all users is C:ProgramDataMicrosoftWindowsStart MenuProgramsStartUp.
The following Registry keys can be used to set startup folder items for persistence:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
The following Registry keys can control automatic startup of services during boot:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServices
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServices
Using policy settings to specify startup programs creates corresponding values in either of two Registry keys:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
Programs listed in the load value of the registry key HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows run automatically for the currently logged-on user.
By default, the multistring BootExecute value of the registry key HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession Manager is set to autocheck autochk *. This value causes Windows, at startup, to check the file-system integrity of the hard disks if the system has been shut down abnormally. Adversaries can add other programs or processes to this registry value which will automatically launch at boot.
Adversaries can use these configuration locations to execute malware, such as remote access tools, to maintain persistence through system reboots. Adversaries may also use Masquerading to make the Registry entries look as if they are associated with legitimate programs.
Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the “run keys” in the Registry or startup folder will cause the program referenced to be executed when a user logs in.(Citation: Microsoft Run Key) These programs will be executed under the context of the user and will have the account’s associated permissions level.
The following run keys are created by default on Windows systems:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnce
Run keys may exist under multiple hives.(Citation: Microsoft Wow6432Node 2018)(Citation: Malwarebytes Wow6432Node 2016) The HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunOnceEx is also available but is not created by default on Windows Vista and newer. Registry run key entries can reference programs directly or list them as a dependency.(Citation: Microsoft Run Key) For example, it is possible to load a DLL at logon using a “Depend” key with RunOnceEx: reg add HKLMSOFTWAREMicrosoftWindowsCurrentVersionRunOnceEx 001Depend /v 1 /d "C:tempevil[.]dll" (Citation: Oddvar Moe RunOnceEx Mar 2018)
Placing a program within a startup folder will also cause that program to execute when a user logs in. There is a startup folder location for individual user accounts as well as a system-wide startup folder that will be checked regardless of which user account logs in. The startup folder path for the current user is C:Users\[Username]AppDataRoamingMicrosoftWindowsStart MenuProgramsStartup. The startup folder path for all users is C:ProgramDataMicrosoftWindowsStart MenuProgramsStartUp.
The following Registry keys can be used to set startup folder items for persistence:
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerShell Folders
* HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
The following Registry keys can control automatic startup of services during boot:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServicesOnce
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServices
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunServices
Using policy settings to specify startup programs creates corresponding values in either of two Registry keys:
* HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
* HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun
Programs listed in the load value of the registry key HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows run automatically for the currently logged-on user.
By default, the multistring BootExecute value of the registry key HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession Manager is set to autocheck autochk *. This value causes Windows, at startup, to check the file-system integrity of the hard disks if the system has been shut down abnormally. Adversaries can add other programs or processes to this registry value which will automatically launch at boot.
Adversaries can use these configuration locations to execute malware, such as remote access tools, to maintain persistence through system reboots. Adversaries may also use Masquerading to make the Registry entries look as if they are associated with legitimate programs.
Adversaries may match or approximate the name or location of legitimate files or 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). In containerized environments, this may also be done by creating a resource in a namespace that matches the naming convention of a container pod or cluster. Alternatively, a file or container image name given may be a close approximation to legitimate programs/images or something innocuous.
Adversaries may also use the same icon of the file they are trying to mimic.
Adversaries may match or approximate the name or location of legitimate files or 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). In containerized environments, this may also be done by creating a resource in a namespace that matches the naming convention of a container pod or cluster. Alternatively, a file or container image name given may be a close approximation to legitimate programs/images or something innocuous.
Adversaries may also use the same icon of the file they are trying to mimic.
Adversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in persistence and execution.
Access to specific areas of the Registry depends on account permissions, some requiring administrator-level access. The built-in Windows command-line utility Reg may be used for local or remote Registry modification. (Citation: Microsoft Reg) Other tools may also be used, such as a remote access tool, which may contain functionality to interact with the Registry through the Windows API.
Registry modifications may also include actions to hide keys, such as prepending key names with a null character, which will cause an error and/or be ignored when read via Reg or other utilities using the Win32 API. (Citation: Microsoft Reghide NOV 2006) Adversaries may abuse these pseudo-hidden keys to conceal payloads/commands used to maintain persistence. (Citation: TrendMicro POWELIKS AUG 2014) (Citation: SpectorOps Hiding Reg Jul 2017)
The Registry of a remote system may be modified to aid in execution of files as part of lateral movement. It requires the remote Registry service to be running on the target system. (Citation: Microsoft Remote) Often Valid Accounts are required, along with access to the remote system’s SMB/Windows Admin Shares for RPC communication.
Adversaries may modify and/or disable security tools to avoid possible detection of their malware/tools and activities. This may take many forms, such as killing security software processes or services, modifying / deleting Registry keys or configuration files so that tools do not operate properly, or other methods to interfere with security tools scanning or reporting information. Adversaries may also disable updates to prevent the latest security patches from reaching tools on victim systems.(Citation: SCADAfence_ransomware)
Adversaries may also tamper with artifacts deployed and utilized by security tools. Security tools may make dynamic changes to system components in order to maintain visibility into specific events. For example, security products may load their own modules and/or modify those loaded by processes to facilitate data collection. Similar to Indicator Blocking, adversaries may unhook or otherwise modify these features added by tools (especially those that exist in userland or are otherwise potentially accessible to adversaries) to avoid detection.(Citation: OutFlank System Calls)(Citation: MDSec System Calls)
Adversaries may also focus on specific applications such as Sysmon. For example, the “Start” and “Enable” values in HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlWMIAutologgerEventLog-Microsoft-Windows-Sysmon-Operational may be modified to tamper with and potentially disable Sysmon logging.(Citation: disable_win_evt_logging)
On network devices, adversaries may attempt to skip digital signature verification checks by altering startup configuration files and effectively disabling firmware verification that typically occurs at boot.(Citation: Fortinet Zero-Day and Custom Malware Used by Suspected Chinese Actor in Espionage Operation)(Citation: Analysis of FG-IR-22-369)
In cloud environments, tools disabled by adversaries may include cloud monitoring agents that report back to services such as AWS CloudWatch or Google Cloud Monitor.
Furthermore, although defensive tools may have anti-tampering mechanisms, adversaries may abuse tools such as legitimate rootkit removal kits to impair and/or disable these tools.(Citation: chasing_avaddon_ransomware)(Citation: dharma_ransomware)(Citation: demystifying_ryuk)(Citation: doppelpaymer_crowdstrike) For example, adversaries have used tools such as GMER to find and shut down hidden processes and antivirus software on infected systems.(Citation: demystifying_ryuk)
Additionally, adversaries may exploit legitimate drivers from anti-virus software to gain access to kernel space (i.e. Exploitation for Privilege Escalation), which may lead to bypassing anti-tampering features.(Citation: avoslocker_ransomware)
Adversaries may communicate using application layer protocols associated with web traffic 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 HTTP/S(Citation: CrowdStrike Putter Panda) and WebSocket(Citation: Brazking-Websockets) that carry web traffic may be very common in environments. HTTP/S packets have many fields and headers in which data can be concealed. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.
Adversaries may communicate using application layer protocols associated with web traffic 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 HTTP/S(Citation: CrowdStrike Putter Panda) and WebSocket(Citation: Brazking-Websockets) that carry web traffic may be very common in environments. HTTP/S packets have many fields and headers in which data can be concealed. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.
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