AHTeam EP Protector 03 fake Borland Delphi 60 70 FEUERRADER additional

Hunt Hypothesis

This rule identifies executable files exhibiting characteristics of the AHTeam EP Protector, specifically those masquerading as Borland Delphi binaries, which adversaries may use to obfuscate malicious payloads and evade static analysis. Proactively hunting for these specific protector signatures allows the SOC team to detect low-severity, potentially stealthy malware variants that leverage known compiler frameworks to blend in with legitimate software within the Azure Sentinel environment.

YARA Rule

rule AHTeam_EP_Protector_03_fake_Borland_Delphi_60_70_FEUERRADER_additional: PEiD
{
    strings:
        $a = { 90 ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? 90 FF E0 53 8B D8 33 C0 A3 00 00 00 00 6A 00 E8 00 00 00 FF A3 00 00 00 00 A1 00 00 00 00 A3 00 00 00 00 33 C0 A3 }
    condition:
        $a 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 Delphi Application Deployment via Group Policy

  • Scenario: An IT administrator deploys a legacy internal inventory tool or point-of-sale system written in Borland Delphi 6/7 to a fleet of Windows machines using Group Policy Objects (GPO) or a configuration management tool like SCCM. The binary retains its original Delphi header and version strings, which the YARA rule identifies as a “fake” or specific variant of Delphi 60/70.
  • Filter/Exclusion: Exclude files located in standard application directories (e.g., C:\Program Files\, C:\Program Files (x86)\) that have a valid digital signature from a known internal publisher or match a specific file hash list of approved legacy applications.

• Antivirus/Endpoint Protection Quarantine Scans

  • Scenario: The endpoint protection agent (e.g., Microsoft Defender for Endpoint, CrowdStrike Falcon) performs a deep scan of the quarantine folder or the C:\ProgramData\ directory where previously quarantined or staged installers reside. These files often retain their original headers and may be partially unpacked or in a state that triggers the “FEUERRADER” (German for “error reader”) string match, which is common in older Delphi error handling routines.
  • Filter/Exclusion: Exclude paths containing Quarantine, Temp, Cache, or ProgramData where the file is not currently executing (i.e., filter by process parent being the AV agent or a service like MsMpEng.exe or FalconSensor.exe).

• Scheduled Backup or Archiving Jobs

  • Scenario: A scheduled task (e.g., BackupLegacyApps) runs nightly to copy older application binaries from network shares or local drives to an archive repository. During the copy operation, the file is