BlackShades Server

Hunt Hypothesis

This detection rule identifies communication patterns associated with the BlackShades remote access trojan (RAT) server, which adversaries leverage to establish persistent command-and-control channels for lateral movement and data exfiltration. Proactively hunting for this behavior in Azure Sentinel is critical because early identification of these low-severity connections allows SOC teams to isolate compromised endpoints before the RAT escalates its activities or expands its foothold within the network.

YARA Rule

rule BlackShades : Trojan
{
	meta:
		author="Kevin Falcoz"
		date="26/06/2013"
		description="BlackShades Server"
		
	strings:
		$signature1={62 73 73 5F 73 65 72 76 65 72}
		$signature2={43 4C 49 43 4B 5F 44 45 4C 41 59 00 53 43 4B 5F 49 44}
		$signature3={6D 6F 64 49 6E 6A 50 45}
		
	condition:
		$signature1 and $signature2 and $signature3
}

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 3 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the BlackShades Server detection rule in an enterprise environment, along with suggested filters or exclusions:

• Scenario: Automated Patch Management Deployment

  • Context: Enterprise patching tools like Microsoft Endpoint Configuration Manager (MECM/SCCM) or Ivanti frequently deploy updates to thousands of endpoints. These agents often establish persistent connections to central management servers that may share IP ranges or behavioral signatures with known BlackShades C2 infrastructure, particularly if the vendor utilizes shared cloud hosting providers (e.g., Azure/AWS) common to both legitimate tools and threat actors.
  • Suggested Filter: Create an exclusion based on the specific Process Name (ccmexec.exe for SCCM or IvantiAgent.exe) combined with the known internal IP address of the Patch Management Server. Additionally, filter out traffic where the User-Agent string contains “Microsoft-ConfigurationManager” or “Ivanti”.

• Scenario: Scheduled Backup and Data Replication Jobs

  • Context: Enterprise backup solutions such as Veeam Backup & Replication, Commvault, or Rubrik run scheduled jobs during off-hours to replicate data to cloud storage or secondary data centers. These agents initiate long-lived, high-volume connections that can mimic the “beacon” behavior of BlackShades malware, especially if the backup destination is a public cloud endpoint with similar TLS certificate characteristics.
  • Suggested Filter: Exclude traffic originating from specific Service Accounts (e.g., svc-veeam-backup) running during defined maintenance windows (e.g., 02:00–06:00 UTC). Implement a filter that whitelists the destination FQDNs of known backup repositories (e.g., *.veeam.com or specific S3 bucket endpoints) and validates the process path against