ThreatFox: ValleyRAT IOCs

Hunt Hypothesis

This hunt hypothesis targets adversary behavior where ValleyRAT establishes a foothold through phishing emails to enable command-and-control communication, data exfiltration, and arbitrary command execution on infected endpoints. A SOC team should proactively hunt for these indicators in Azure Sentinel because the high severity of this remote access trojan allows attackers to maintain persistent access and silently extract sensitive information before detection occurs.

IOC Summary

Malware Family: ValleyRAT Total IOCs: 3 IOC Types: sha256_hash, sha1_hash, md5_hash

Type	Value	Threat Type	First Seen	Confidence
sha1_hash	`3249538fbf42402e1e5bedddba234e1755b3e975`	payload	2026-08-07	95%
md5_hash	`2b1caed38122d1e0336af79b88c5801b`	payload	2026-08-07	95%
sha256_hash	`552497b4c1f9b3cf5514ce59292a1f715f3673c375fd1944bb5930f646383e41`	payload	2026-08-07	95%

KQL: Hash Hunt

// Hunt for files matching known malicious hashes
// Source: ThreatFox - ValleyRAT
let malicious_hashes = dynamic(["3249538fbf42402e1e5bedddba234e1755b3e975", "2b1caed38122d1e0336af79b88c5801b", "552497b4c1f9b3cf5514ce59292a1f715f3673c375fd1944bb5930f646383e41"]);
DeviceFileEvents
| where SHA256 in (malicious_hashes) or SHA1 in (malicious_hashes) or MD5 in (malicious_hashes)
| project Timestamp, DeviceName, FileName, FolderPath, SHA256, InitiatingProcessFileName
| order by Timestamp desc

Required Data Sources

Sentinel Table	Notes
`DeviceFileEvents`	Ensure this data connector is enabled

References

ThreatFox — ValleyRAT

False Positive Guidance

Here are 4 specific false positive scenarios for the ThreatFox: ValleyRAT IOCs detection rule, tailored to a legitimate enterprise environment:

Scenario: Automated Patch Deployment via Admin Workstations
- Context: System administrators frequently use tools like Microsoft Endpoint Configuration Manager (MECM) or Ansible on jump hosts to push security patches. These tools often initiate outbound HTTPS connections to update repositories that share the same IP ranges or domain suffixes as ValleyRAT’s known C2 infrastructure, mimicking the “command-and-control” traffic pattern of the RAT.
- Suggested Filter/Exclusion: Create a whitelist exclusion for specific admin service accounts (e.g., svc-patch-deploy) and restrict the rule to exclude traffic originating from the dedicated “Patch Management VLAN.” Alternatively, filter out alerts where the process name matches known management tools like ccmexec.exe or ansible-playbook.
Scenario: Scheduled Cloud Backup Synchronization
- Context: Enterprise backup solutions such as Veeam Backup & Replication or Rubrik run scheduled jobs during off-hours to exfiltrate data to cloud storage. The high-volume, periodic outbound traffic generated by these agents can trigger the “data exfiltration” logic of the ValleyRAT rule, especially if the backup destination IP is a known public cloud provider overlapping with ValleyRAT IOCs.
- Suggested Filter/Exclusion: Implement a time-based exclusion (e.g., 02:00–06:00 local time) for processes named VeeamAgent.exe or rubrik-agent. Additionally, exclude traffic destined for known backup S3 buckets or Azure Blob Storage endpoints that match the rule’s IOCs.
Scenario: Phishing Simulation Campaigns
- Context: Security teams regularly conduct internal phishing