Shifu

Hunt Hypothesis

This detection identifies the presence of the Shifu malware family by leveraging a specific YARA signature to flag known malicious code artifacts within the environment. Proactively hunting for this indicator in Azure Sentinel is essential to validate the rule’s efficacy and ensure early discovery of potential low-severity threats before they escalate into broader incidents.

YARA Rule

rule Shifu : banking {
	meta:
		reference = "https://blogs.mcafee.com/mcafee-labs/japanese-banking-trojan-shifu-combines-malware-tools/"
		author = "McAfee Labs"
	strings:
		$b = "RegCreateKeyA"
		$a = "CryptCreateHash"
		$c = {2F 00 63 00 20 00 73 00 74 00 61 00 72 00 74 00 20 00 22 00 22 00 20 00 22 00 25 00 73 00 22 00 20 00 25 00 73 00 00 00 00 00 63 00 6D 00 64 00 2E 00 65 00 78 00 65 00 00 00 72 00 75 00 6E}
		$d = {53 00 6E 00 64 00 56 00 6F 00 6C 00 2E 00 65 00 78 00 65}
		$e = {52 00 65 00 64 00 69 00 72 00 65 00 63 00 74 00 45 00 58 00 45}
	condition:
		all of them
}

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 5 string patterns in its detection logic.

References

• https://blogs.mcafee.com/mcafee-labs/japanese-banking-trojan-shifu-combines-malware-tools/
• Source Rule

False Positive Guidance

Here are 5 specific false positive scenarios for the Shifu detection rule in an enterprise environment, including suggested filters and exclusions:

• Antivirus Scheduled Scans and Updates

  • Scenario: Enterprise Endpoint Protection suites (e.g., CrowdStrike Falcon, Microsoft Defender for Endpoint) frequently execute scheduled scans or download signature updates during off-hours. These processes often spawn child processes that match the Shifu YARA signatures due to similar memory structures or file I/O patterns associated with security agents.
  • Filter/Exclusion: Create an exclusion rule based on the parent process name and path. Exclude events where ParentProcessName is C:\Program Files\CrowdStrike\fs.exe (CrowdStrike) or MsMpEng.exe (Defender), specifically when the event occurs between 02:00 and 05:00 local time.

• Software Deployment via SCCM/Intune

  • Scenario: System Center Configuration Manager (SCCM) or Microsoft Intune agents push application updates to workstations. During these deployments, the ccmexec.exe service launches temporary installers that may trigger the Shifu rule if they utilize specific DLL injection techniques or registry modifications common in the detection logic.
  • Filter/Exclusion: Filter for processes launched by ccmexec.exe where the command line arguments contain keywords like /install, /update, or reference to the Software Center catalog. Additionally, exclude known deployment paths such as C:\Windows\CCM\Cache.

• Database Backup and Maintenance Jobs

  • Scenario: Scheduled SQL Server maintenance tasks (e.g., backup jobs running via sqlagent.exe or third-party tools like Veeam) often generate high-volume file writes and memory allocations. If the Shifu rule detects specific binary structures common in database engine operations, these routine backups will