ThreatFox: DCRat IOCs

Hunt Hypothesis

This hunt detects adversary activity involving known DCRat remote access trojan indicators, specifically targeting malicious network connections and file artifacts linked to this threat family. Proactively hunting for these IOCs in Azure Sentinel is critical to identify early-stage lateral movement or command-and-control communications that could lead to data exfiltration before the malware fully establishes persistence on compromised endpoints.

IOC Summary

Malware Family: DCRat Total IOCs: 2 IOC Types: ip:port

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - DCRat
let malicious_ips = dynamic(["46.246.6.7", "158.94.210.161"]);
CommonSecurityLog
| where DestinationIP in (malicious_ips) or SourceIP in (malicious_ips)
| project TimeGenerated, SourceIP, DestinationIP, DestinationPort, DeviceAction, Activity
| order by TimeGenerated desc

KQL: Ip Hunt Device

// Hunt in Defender for Endpoint network events
let malicious_ips = dynamic(["46.246.6.7", "158.94.210.161"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — DCRat

False Positive Guidance

Here are 3-5 specific false positive scenarios for the ThreatFox: DCRat IOCs detection rule, along with suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Scheduled Antivirus or EDR Full Scan Execution

  • Context: Enterprise Endpoint Detection and Response (EDR) agents like CrowdStrike Falcon, Microsoft Defender for Endpoint, or Symantec Endpoint Protection often perform scheduled full scans during off-hours. These tools frequently communicate with their management consoles using specific IP addresses or domains that may overlap with DCRat’s known IOCs (e.g., shared cloud infrastructure IPs).
  • Suggested Filter/Exclusion: Create a rule exclusion based on the Process Name and Parent Process. Exclude alerts where the process name matches FalconSensor.exe, MsMpEng.exe, or Symantec Antivirus and the parent process is the OS scheduler (svchost.exe running under the System account). Additionally, filter out traffic originating from internal IP ranges designated for Security Management Servers.

• Scenario: Automated Patch Deployment via Configuration Management Tools

  • Context: During monthly maintenance windows, tools like Microsoft SCCM (Configuration Manager) or Ansible Tower push updates to endpoints. These tools often utilize specific update servers or download repositories that share IP ranges with the DCRat command-and-control infrastructure identified in the ThreatFox feed. The detection logic may flag these legitimate download connections as malicious C2 traffic.
  • Suggested Filter/Exclusion: Implement a time-based exclusion window (e.g., 02:00 - 06:00 on Tuesdays and Thursids) for alerts triggered by processes named ccmexec.exe or ansible-runner. Alternatively, add the specific IP addresses of your internal SCCM Distribution Points to an allow-list within the detection