Detect HTML Help Using InfoTech Storage Handlers: endpointEndpointNoneversion:15
The following analytic detects the execution of hh.exe (HTML Help) using InfoTech Storage Handlers to load Windows script code from a Compiled HTML Help (CHM) file. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because it can be used to execute malicious scripts embedded within CHM files, potentially leading to code execution. If confirmed malicious, this technique could allow an attacker to execute arbitrary code, escalate privileges, or persist within the environment.
Windows System Binary Proxy Execution Compiled HTML File Decompile: endpointEndpointNoneversion:15
The following analytic detects the use of the decompile parameter with the HTML Help application (HH.exe). This behavior is identified through Endpoint Detection and Response (EDR) telemetry, focusing on command-line executions involving the decompile parameter. This activity is significant because it is an uncommon command and has been associated with APT41 campaigns, where it was used to unpack HTML help files for further malicious actions. If confirmed malicious, this technique could allow attackers to execute arbitrary commands, potentially leading to further compromise and persistence within the environment.
Detect HTML Help Renamed: endpointEndpointNoneversion:14
The following analytic detects instances where hh.exe (HTML Help) has been renamed and is executing a Compiled HTML Help (CHM) file. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and original file names. This activity is significant because attackers can use renamed hh.exe to execute malicious scripts embedded in CHM files, potentially leading to code execution. If confirmed malicious, this technique could allow attackers to run arbitrary scripts, escalate privileges, or persist within the environment, posing a significant security risk.
Detect HTML Help Spawn Child Process: endpointEndpointNoneversion:16
The following analytic detects the execution of hh.exe (HTML Help) spawning a child process, indicating the use of a Compiled HTML Help (CHM) file to execute Windows script code. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events where hh.exe is the parent process. This activity is significant as it may indicate an attempt to execute malicious scripts via CHM files, a known technique for bypassing security controls. If confirmed malicious, this could lead to unauthorized code execution, potentially compromising the system.
Detect HTML Help URL in Command Line: endpointEndpointNoneversion:17
The following analytic detects the execution of hh.exe (HTML Help) loading a Compiled HTML Help (CHM) file from a remote URL. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions containing URLs. This activity is significant as it can indicate an attempt to execute malicious scripts via CHM files, potentially leading to unauthorized code execution. If confirmed malicious, this could allow an attacker to run scripts using engines like JScript or VBScript, leading to further system compromise or data exfiltration.
