DingBoysPElockPhantasmv15b3

Hunt Hypothesis

This detection identifies the presence of the Phantasm variant within the DingBoy family of malware, which utilizes PE locking mechanisms to obscure its execution and evade standard signature-based defenses. A proactive hunt is essential in Azure Sentinel to uncover early-stage infections that may bypass initial perimeter controls, allowing the SOC team to isolate compromised endpoints before lateral movement or data exfiltration occurs.

YARA Rule

rule DingBoysPElockPhantasmv15b3
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 9C 55 57 56 52 51 53 9C FA E8 00 00 00 00 5D 81 ED 5B 53 40 00 B0 }

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

Here are 4 specific false positive scenarios for the DingBoysPElockPhantasmv15b3 detection rule, along with targeted filters and exclusions:

• Scenario: Scheduled Antivirus Database Updates

  • Context: Enterprise antivirus solutions (e.g., Microsoft Defender ATP or Symantec Endpoint Protection) frequently download new definition updates during off-hours. These updates often involve the extraction of compressed PE files that mimic the structural signatures of the DingBoys malware family, triggering the YARA rule on the temporary update cache folders.
  • Filter/Exclusion: Exclude file paths containing known antivirus update directories (e.g., C:\ProgramData\Microsoft\Windows Defender\Platform\ or C:\Symantec Endpoint Protection\Content) and filter out processes running under the specific service accounts associated with these vendors (e.g., NT SERVICE\MsMpSvc).

• Scenario: Automated Patch Deployment via SCCM/Intune

  • Context: During monthly patch cycles, System Center Configuration Manager (SCCM) or Microsoft Intune pushes application updates that include new PE executables. The deployment agent often unpacks these binaries to a staging folder before installation, where the file structure matches the “phantasm” signature of the detection rule.
  • Filter/Exclusion: Create an exclusion for processes spawned by ccmsetup.exe (SCCM) or IntuneManagementExtension.exe. Additionally, exclude any files located in temporary deployment folders such as C:\Windows\CCMCache\ or %TEMP%\IntuneDeployment.

• Scenario: Enterprise Backup and Archiving Jobs

  • Context: Scheduled backup jobs (e.g., Veeam Agent for Windows or Acronis Cyber Protect) scan the file system to create incremental backups. During this process, they may instantiate temporary PE lock files or archive manifests