ThreatFox: DCRat IOCs

Hunt Hypothesis

This detection rule identifies adversary activity involving known DCRat remote access trojan indicators, which are frequently used to establish persistent command and control channels on compromised endpoints. Proactively hunting for these IOCs in Azure Sentinel is critical because early identification of DCRat presence allows the SOC team to rapidly isolate affected systems before attackers can exfiltrate sensitive data or pivot laterally across the network.

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(["64.89.161.196", "78.17.71.8"]);
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(["64.89.161.196", "78.17.71.8"]);
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 5 specific false positive scenarios for the ThreatFox: DCRat IOCs detection rule, along with suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Legitimate Remote Management via Endpoint Security Consoles

  • Context: Enterprise Endpoint Detection and Response (EDR) agents like CrowdStrike Falcon, Microsoft Defender for Endpoint, or SentinelOne often utilize DCRat-like communication patterns to push configuration updates, deploy policies, or perform remote command execution from the central management server. These legitimate administrative actions may match the specific IOCs (hashes or network signatures) defined in the ThreatFox package.
  • Filter/Exclusion: Create a filter that excludes processes originating from known EDR service executables (e.g., C:\Program Files\CrowdStrike\FalconSensor\fs_qr.exe or C:\Windows\System32\DPSvc.dll) when the parent process is the EDR management agent. Alternatively, whitelist the specific SHA-256 hashes of these known good binaries within the detection logic.

• Scenario: Scheduled Backup and Replication Jobs

  • Context: Automated backup solutions such as Veeam, Rubrik, or Commvault frequently run scheduled jobs (e.g., nightly incremental backups) that utilize DCRat-based agents for data transfer and orchestration. These jobs often trigger network connections to central management nodes that mimic the IOCs associated with DCRat, leading to alerts during peak backup windows.
  • Filter/Exclusion: Implement a time-based exclusion rule that suppresses this alert between 01:00 AM and 06:00 AM (local time) for processes belonging to backup service accounts (e.g., VeeamBackupService, RubrikAgent). Additionally, exclude traffic originating from the specific IP ranges of