GameGuardv20065xxexesignbyhot UNP

Hunt Hypothesis

This rule detects the execution of a specific version of the GameGuard anti-cheat component, which adversaries may leverage to establish a persistent foothold or hide malicious activity within legitimate game processes. Proactively hunting for this signature allows the SOC team to identify potential low-severity anomalies or unauthorized game client installations that could serve as initial access vectors or cover for stealthy payload delivery.

YARA Rule

rule GameGuardv20065xxexesignbyhot_UNP
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 31 FF 74 06 61 E9 4A 4D 50 30 5A BA 7D 00 00 00 80 7C 24 08 01 E9 00 00 00 00 60 BE 00 }

condition:
		$a0 at pe.entry_point
}

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

• Legitimate Game Launcher Updates (Steam/Epic/Ubisoft)

  • Scenario: Major game launchers (e.g., Steam, Epic Games Launcher, Ubisoft Connect) frequently update their anti-cheat modules or game executables in the background. The GameGuard signature often matches specific versioned executables (e.g., GameGuardv20065xx.exe) that are temporarily signed by Hotfix or specific vendor keys during the update process, triggering the “UNP” (Unsigned/Not-Pinned) alert.
  • Filter/Exclusion: Exclude processes where the parent process is a known launcher (e.g., Steam.exe, EGLauncher.exe, UbisoftConnect.exe) and the file path contains \games\ or \library\. Alternatively, whitelist specific known-good SHA-256 hashes of the GameGuard executables for the major titles.

• Scheduled Anti-Cheat Integrity Checks

  • Scenario: Many enterprise environments with gaming PCs or dev/test machines use scheduled tasks (e.g., Task Scheduler or cron on Linux) to run integrity checks or clean up temporary anti-cheat files. This can involve executing a copy of the GameGuard binary or a related helper script that re-signs or verifies the module, appearing as an unexpected execution if the original signature is stripped or cached.
  • Filter/Exclusion: Exclude executions where the parent process is svchost.exe (specifically the Schedule service) or TaskScheduler.exe, and the command line contains keywords like verify, integrity, or cleanup.

• Developer/Tester Local Builds (CI/CD Artifacts)

  • Scenario: In game development studios or QA environments, developers often run local builds of games that include custom or modified GameGuard modules.