AHpack01FEUERRADER

Hunt Hypothesis

This rule identifies potential memory corruption or buffer overflow attempts by detecting specific error string patterns often left behind by packed executables or shellcode during execution. Proactively hunting for these indicators helps the SOC team uncover stealthy malware that may be evading traditional signature-based detections by manipulating memory states or hiding its payload within standard error handling routines.

YARA Rule

rule AHpack01FEUERRADER
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 68 54 [3] B8 48 [3] FF 10 68 B3 [3] 50 B8 44 [3] FF 10 68 00 [3] 6A 40 FF D0 89 05 CA [3] 89 C7 BE 00 10 [2] 60 FC B2 80 31 DB A4 B3 02 E8 6D 00 00 00 73 F6 31 C9 E8 64 00 00 00 73 1C 31 C0 E8 5B 00 00 00 73 23 B3 02 41 }

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

• Legacy Application Maintenance (Adobe/Office Suites):

  • Scenario: The rule likely targets specific error handling or reader components within legacy software. Legitimate installations of Adobe Acrobat Reader or Microsoft Office may contain DLLs or executables with naming conventions or binary signatures that match the AHpack01FEUERRADER pattern, especially during automated updates or repair tasks.
  • Filter/Exclusion: Exclude files located in C:\Program Files\Adobe\ or C:\Program Files\Microsoft Office\ where the process name is acrord32.exe, WINWORD.EXE, or EXCEL.EXE, and the file path matches known vendor update directories (e.g., \Updates\, \Shared\).

• Antivirus/Endpoint Protection Self-Check:

  • Scenario: Endpoint Detection and Response (EDR) or Antivirus agents (e.g., CrowdStrike Falcon, SentinelOne, or Microsoft Defender for Endpoint) often perform self-integrity checks or load specific “error reader” or diagnostic modules during scheduled health checks. These modules may reside in temporary directories or system32 with names that trigger the YARA rule.
  • Filter/Exclusion: Exclude processes spawned by known security agents (e.g., FalconSensor.exe, SentinelOne.exe, MsMpEng.exe) where the parent process is the main agent service and the file path is within the vendor’s installation directory (e.g., C:\ProgramData\CrowdStrike\, C:\Program Files\SentinelOne\).

• Scheduled Database Maintenance Jobs:

  • Scenario: Database management tools like SQL Server Management Studio (SSMS) or Oracle SQL Developer may launch background processes for log analysis, error reporting, or reader utilities during scheduled maintenance windows (e.g., nightly backups or index rebuilds). These utilities might be named