ThreatFox: RatonRAT IOCs

Hunt Hypothesis

This hunt identifies adversary activity involving the five specific indicators of compromise linked to the RatonRAT remote access trojan within Azure Sentinel logs. Proactively hunting for these signatures is critical because early detection of this RAT enables the SOC team to isolate compromised endpoints before attackers can establish persistent command-and-control channels or exfiltrate sensitive data.

IOC Summary

Malware Family: RatonRAT Total IOCs: 5 IOC Types: sha256_hash, md5_hash, ip:port, sha1_hash

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - RatonRAT
let malicious_ips = dynamic(["81.177.49.127", "158.160.75.185"]);
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(["81.177.49.127", "158.160.75.185"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

KQL: Hash Hunt

// Hunt for files matching known malicious hashes
// Source: ThreatFox - RatonRAT
let malicious_hashes = dynamic(["4db7b73a3650b98b99aa282bf1e16cc1", "16aa5e9cd33302fb4bba5f5fe61b9dcef4e6e1a777098985eca17e5a6f075234", "3f762a0e0d991b182032fcf13cb94c75a61fe47b"]);
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

References

• ThreatFox — RatonRAT

False Positive Guidance

Here are specific false positive scenarios for the ThreatFox: RatonRAT IOCs detection rule, tailored for an enterprise environment:

• Endpoint Protection Scanning of Quarantined Archives

  • Scenario: The organization’s EDR solution (e.g., CrowdStrike Falcon or Microsoft Defender for Endpoint) performs a scheduled deep scan of the C:\Quarantine directory. This directory contains archived versions of legacy applications and known benign files that happen to share hash values with RatonRAT IOCs due to common open-source libraries (e.g., specific versions of libcurl or openssl) embedded within them.
  • Filter/Exclusion: Exclude file paths containing \Quarantine\, \Temp\, and \Staging\. Additionally, filter out alerts where the process name is the EDR scanner itself (e.g., C:\Program Files\CrowdStrike\fs.exe or MsMpEng.exe) rather than a user-facing application.

• Software Deployment via Configuration Management

  • Scenario: During a monthly patch cycle, the IT Operations team uses Ansible or SCCM (System Center Configuration Manager) to deploy a new internal utility tool. The deployment package includes a pre-compiled binary that matches one of the RatonRAT network connection IOCs because it utilizes a standard HTTP client library with a matching User-Agent string or certificate thumbprint found in the ThreatFox feed.
  • Filter/Exclusion: Create an exclusion for processes spawned by known deployment agents (e.g., Ansible.exe, ccmexec.exe, TaskScheduler) and restrict the rule to trigger only on non-administrative user sessions, or exclude specific IP ranges associated with internal patch management servers.

• Scheduled Backup and Snapshot Operations

  • Scenario: A nightly job executed by **Veeam