VMProtect07x08PolyTech

Hunt Hypothesis

This rule detects the presence of VMProtect-packed executables, a common obfuscation technique used by adversaries to hide malicious code and evade static analysis. Proactively hunting for these artifacts in Azure Sentinel helps identify potentially compromised workloads or staging environments where attackers may be deploying packed binaries to establish persistence or execute payloads.

YARA Rule

rule VMProtect07x08PolyTech
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 5B 20 56 4D 50 72 6F 74 65 63 74 20 76 20 30 2E 38 20 28 43 29 20 50 6F 6C 79 54 65 63 68 20 5D }

condition:
		$a0
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Legacy Application Deployment via Group Policy: When deploying older, performance-critical line-of-business applications (e.g., specific versions of SAP GUI, legacy CAD tools, or financial modeling software) that were compiled with VMProtect to prevent reverse engineering, the executable files may land in standard user directories or temp folders during installation.

  • Filter/Exclusion: Exclude paths under C:\Program Files\ and C:\Program Files (x86)\ for known legacy application vendors, or whitelist specific executable names (e.g., sapgui.exe, legacy_modeler.exe) if they are consistently detected and verified as clean.

• Scheduled Backup or Archiving Jobs: Enterprise backup solutions (e.g., Veeam, Commvault, or Windows Server Backup) or custom PowerShell scripts that archive application binaries to network shares or local temp directories for integrity verification may temporarily copy VMProtect-protected executables to locations that match the YARA rule’s path or context criteria.

  • Filter/Exclusion: Exclude files located in known backup staging directories (e.g., C:\Backup\Staging\, \\fileserver\backup\) or exclude processes initiated by backup service accounts (e.g., vsserv.exe, commvault_agent.exe) if the rule triggers on file creation events.

• Third-Party Plugin or Add-on Installation: Installing plugins for IDEs (e.g., Visual Studio, JetBrains) or browser extensions that bundle native C++/C# components protected by VMProtect for anti-tampering. These components are often extracted to user-specific app data folders during installation.

  • Filter/Exclusion: Exclude paths under %LOCALAPPDATA%\ and %APPDATA%\ for known plugin hosts (e.g., VisualStudio\Extensions\, JetBrains\Plugins\) or whitelist specific plugin directory structures if the YARA rule is path