ThreatFox: DCRat IOCs

Hunt Hypothesis

This hunt targets adversary behavior involving the execution of DCRat remote access tools and their associated network communications to identify potential command-and-control activity within the environment. Proactively hunting for these specific IOCs in Azure Sentinel is critical because early detection of this high-severity threat allows the SOC team to isolate compromised endpoints before attackers can establish persistent lateral movement or exfiltrate sensitive data.

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(["141.94.121.162", "144.172.88.128"]);
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(["141.94.121.162", "144.172.88.128"]);
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 in an enterprise environment, along with recommended filters or exclusions:

• Legitimate Remote Desktop Administration via RDP Wrapper

  • Scenario: System administrators frequently use third-party tools like RDP Wrapper Library or Remote Desktop Manager (Devolutions) to manage legacy servers. These tools often spawn helper processes that establish connections to the same IP ranges and ports used by DCRat’s command-and-control infrastructure, specifically when connecting to jump hosts within the corporate DMZ.
  • Filter/Exclusion: Create an exclusion for traffic originating from known administrative workstations (e.g., OU=Admin-Workstations) or specific process names (rdpwrap.exe, DevRemoteManager.exe) communicating with internal IP ranges defined in the “Corporate Infrastructure” asset group, rather than external threat intelligence feeds.

• Automated Patch Management and Software Deployment

  • Scenario: Enterprise deployment tools such as Microsoft Endpoint Configuration Manager (MECM/SCCM) or Ivanti LANDESK execute scheduled jobs to distribute updates. During these windows, the agents may download manifests or communicate with update servers that share IP addresses or domain names with DCRat IOCs, particularly if the organization uses a shared CDN for patch delivery.
  • Filter/Exclusion: Exclude network connections initiated by the ccmexec.exe (SCCM) or lanagent.exe processes during defined maintenance windows (e.g., 02:00–04:00 UTC). Additionally, whitelist specific destination IP ranges associated with the organization’s internal patch management servers.

• Third-Party Backup and Data Synchronization Agents

  • Scenario: Enterprise backup solutions like Veeam Backup & Replication, Commvault, or **Acronis