ThreatFox: DCRat IOCs

Hunt Hypothesis

This hunt detects adversary activity involving the DCRat remote access tool by identifying specific indicators of compromise (IOCs) that signal potential command-and-control or lateral movement within the network. Proactively hunting for these IOCs in Azure Sentinel is critical to rapidly identify and contain early-stage infections, as DCRat’s stealthy nature allows attackers to establish persistent footholds before triggering broader alerting mechanisms.

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(["194.182.79.61", "46.246.82.10"]);
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(["194.182.79.61", "46.246.82.10"]);
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, including suggested filters and exclusions tailored for an enterprise environment:

• Endpoint Protection Scans by CrowdStrike Falcon or Microsoft Defender

  • Scenario: The EDR agent (e.g., CrowdStrike Falcon Sensor) performs a scheduled deep scan of the C:\Program Files\DCRat directory or executes a specific remediation script that matches the DCRat hash signature. This often occurs during off-hours maintenance windows when the agent updates its local database with new IOCs.
  • Filter/Exclusion: Create an exclusion based on the Process Name (FalconSensor.exe, MsMpEng.exe) and Parent Process (the EDR service itself). Additionally, exclude alerts where the User Context is a system account (e.g., NT AUTHORITY\SYSTEM or DOMAIN\AdminService) executing during defined maintenance windows (e.g., 02:00–04:00 UTC).

• Automated Patch Deployment via SCCM/Intune

  • Scenario: The IT Operations team deploys a patch or configuration update to the DCRat application using Microsoft Endpoint Configuration Manager (SCCM) or Intune. The deployment engine extracts the installer or runs a PowerShell script that triggers the specific IOCs associated with DCRat, mimicking an active threat detection.
  • Filter/Exclusion: Filter alerts where the Parent Process is ccmsetup.exe (SCCM) or IntuneManagementExtension.exe. Implement a rule exclusion for events occurring within 15 minutes of a known “Patch Tuesday” deployment job ID in the change management system.

• Custom PowerShell Automation Scripts for Inventory

  • Scenario: A scheduled PowerShell script (InventoryCheck.ps1) runs nightly to