ThreatFox: DCRat IOCs

Hunt Hypothesis

This hunt targets adversary behavior involving the execution of DCRat remote access trojan components, specifically monitoring for known indicators of compromise such as malicious process creation and network beaconing. Proactively hunting for these IOCs in Azure Sentinel is critical to rapidly identify early-stage lateral movement and data exfiltration attempts before they escalate into full-scale breaches.

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(["82.47.101.76", "104.225.104.237"]);
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(["82.47.101.76", "104.225.104.237"]);
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 specific false positive scenarios for the ThreatFox: DCRat IOCs detection rule, tailored for a legitimate enterprise environment:

• Enterprise Configuration Management Deployments

  • Scenario: Automated deployment tools like Ansible, Chef, or SCCM (System Center Configuration Manager) frequently push configuration scripts to endpoints. These scripts often utilize PowerShell or batch files that invoke remote management commands, creating network connections and file hashes that match DCRat’s known IOCs (specifically regarding its communication with command-and-control infrastructure).
  • Suggested Filter: Exclude traffic originating from the specific IP ranges of your configuration management servers or whitelist the hash signatures of standard deployment scripts (e.g., Invoke-Command modules) used by these tools.

• Scheduled Remote Monitoring and Health Checks

  • Scenario: IT Operations teams utilize monitoring solutions such as SolarWinds NPM, Datadog, or PRTG Network Monitor. These agents run scheduled jobs (often via Windows Task Scheduler) to perform remote health checks, inventory collection, or log aggregation. The periodic outbound connections from these agents to their central collectors can mimic the beaconing behavior of DCRat malware.
  • Suggested Filter: Create an exclusion for processes running under specific service accounts (e.g., svc_monitor, datadog-agent) and restrict the rule alerting window to exclude known maintenance windows where bulk inventory scans occur.

• Third-Party Remote Support Sessions

  • Scenario: During vendor support engagements, external administrators use remote access tools like TeamViewer, AnyDesk, or Microsoft Quick Assist. When these tools initiate a session to troubleshoot an endpoint, they often spawn background processes that establish persistent connections and exchange diagnostic data, which can trigger the DCRat IOCs associated with remote execution.
  • Suggested Filter: