ThreatFox: ValleyRAT IOCs

Hunt Hypothesis

This hunt targets adversary activity involving specific indicators of compromise linked to the ValleyRAT remote access trojan, which is known for establishing persistent command-and-control channels and exfiltrating sensitive data. The SOC team should proactively search for these IOCs within Azure Sentinel to identify early-stage infections before they escalate into full-scale data breaches or lateral movement events.

IOC Summary

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

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - ValleyRAT
let malicious_ips = dynamic(["43.248.172.115"]);
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(["43.248.172.115"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — ValleyRAT

False Positive Guidance

Here are specific false positive scenarios for the ThreatFox: ValleyRAT IOCs detection rule in an enterprise environment, along with suggested filters or exclusions:

• Endpoint Security Agent Updates: The deployment of new definitions or agent versions by tools like CrowdStrike Falcon, Microsoft Defender for Endpoint (MDE), or SentinelOne often involves downloading and executing scripts that match ValleyRAT hash signatures. Specifically, the update.exe process within the CrowdStrike service may trigger the rule when pulling threat intelligence feeds from the cloud.

  • Suggested Filter: Exclude alerts where the parent process is a known security vendor executable (e.g., C:\Program Files\CrowdStrike\csagent.exe) and the file hash matches the specific update package version released in the last 24 hours.

• Software Deployment via SCCM/MECM: System administrators frequently use Microsoft Endpoint Configuration Manager (MECM) or Ivanti to push internal applications or patches. The ccmexec.exe service often downloads and extracts installer packages that contain shared libraries or components identical to those flagged as ValleyRAT IOCs, particularly during scheduled maintenance windows.

  • Suggested Filter: Create an exclusion for events originating from the CCMExec process ID running under the NT AUTHORITY\SYSTEM account, specifically when the execution path resides within the standard MECM distribution point folders (e.g., C:\Windows\CCMCache).

• Automated Backup and Archiving Jobs: Enterprise backup solutions like Veeam Backup & Replication, Commvault, or Acronis Cyber Protect utilize compression engines that may generate temporary files or execute helper utilities matching the ValleyRAT IOCs. These jobs often run as scheduled tasks (e.g., Task Scheduler entries) during off-hours, triggering detections when processing large data sets containing similar binary