AHTeamEPProtector03fakekkryptor9kryptoraFEUERRADER

Hunt Hypothesis

This rule detects the presence of a specific YARA signature associated with the AHTeamEPProtector03fakekkryptor9kryptoraFEUERRADER artifact, which likely indicates the execution or persistence of a low-severity endpoint protection component or a known benign false positive. Proactively hunting for this signature allows the SOC team to validate the integrity of endpoint agents and distinguish between expected protective processes and potential masquerading malware that may be leveraging similar naming conventions to evade detection.

YARA Rule

rule AHTeamEPProtector03fakekkryptor9kryptoraFEUERRADER
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 90 [46] 90 FF E0 60 E8 [4] 5E B9 00 00 00 00 2B C0 02 04 0E D3 C0 49 79 F8 41 8D 7E 2C 33 46 ?? 66 B9 }

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

• Scenario: The kryptor9 binary (or its specific hash) is executed by the Sysmon or Windows Defender service during a scheduled full system scan or a manual “Scan Now” initiated by an IT administrator via the Server Manager console.

  • Filter/Exclusion: Exclude processes where the parent process is svchost.exe (specifically the WSearch or WSearch service group) or MsMpEng.exe (Microsoft Antimalware Service Executable), and the command line contains arguments related to scanning (e.g., /scan, /full, /quick).

• Scenario: A third-party endpoint protection agent (such as CrowdStrike Falcon, Carbon Black, or Trend Micro Apex One) updates its signature database or launches a helper process named kryptor9 (or a similarly obfuscated name) to perform real-time memory inspection or file decryption tasks during a routine update cycle.

  • Filter/Exclusion: Exclude processes where the parent process is the known agent executable (e.g., FalconSensor.exe, CbService.exe, TmService.exe) and the process path resides in the vendor’s installation directory (e.g., C:\Program Files\CrowdStrike\, C:\Program Files\Trend Micro\).

• Scenario: An enterprise backup solution (such as Veeam Backup & Replication, Acronis Cyber Protect, or Commvault) uses a temporary decryption/encryption helper module named kryptor9 to process encrypted backup chunks or perform deduplication tasks during a scheduled nightly backup job.

  • Filter/Exclusion: Exclude processes where the parent process is the backup service executable (e.g., VeeamBackupSvc.exe, AcronisService.exe, `