HyingsPEArmor075exeHyingCCG

Hunt Hypothesis

This rule detects the execution of the HyingsPEArmor075.exe binary, a known component of the Hying malware family, which often serves as a loader or dropper for subsequent malicious payloads. Proactively hunting for this indicator allows the SOC team to identify early-stage compromise or lateral movement attempts before the malware establishes persistence or exfiltrates data within the Azure environment.

YARA Rule

rule HyingsPEArmor075exeHyingCCG
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 00 00 00 00 00 00 00 00 [2] 00 00 00 00 00 00 [2] 01 00 00 00 00 00 00 00 00 00 56 69 72 74 75 61 6C 41 6C 6C 6F 63 00 00 00 00 00 00 00 00 [19] 00 00 00 00 00 00 00 00 00 74 [3] 00 00 00 00 00 }

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

• Scenario: A developer or DevOps engineer manually executes the HyingsPEArmor075.exe utility from a local drive or network share to apply custom PE header obfuscation or anti-debugging patches to a proprietary application binary during a build verification step.

  • Filter/Exclusion: Exclude alerts where the process path contains \bin\, \tools\, or \build\ and the parent process is a known IDE (e.g., devenv.exe, code.exe) or a build agent (e.g., agent.exe, vstest.console.exe).

• Scenario: A security team runs a scheduled PowerShell script via Task Scheduler to batch-process legacy executables for compatibility testing, invoking HyingsPEArmor075.exe as part of a pipeline that includes other known PE manipulation tools like PEBaker or UPX.

  • Filter/Exclusion: Exclude alerts where the parent process is svchost.exe (indicating Task Scheduler) or powershell.exe with a command line containing specific keywords like -Path, -OutputFile, or -Force, and the working directory is a dedicated test or staging folder (e.g., C:\SecOps\Testing\).

• Scenario: An endpoint detection and response (EDR) agent or a third-party application virtualization tool (such as App-V or ThinApp) temporarily unpacks or transforms binaries in a cache folder, triggering the YARA rule on the transformed HyingsPEArmor075.exe artifact during a routine integrity check.

  • Filter/Exclusion: Exclude alerts where the file path includes common virtualization or cache directories such as \Appx\, \ThinApp\, \Cache\, or \Temp\ and the file size is less than a specific threshold (e.g., < 5MB) to avoid