ThreatFox: BTMOB RAT IOCs

Hunt Hypothesis

This hunt detects adversary behavior characterized by the presence of specific Indicators of Compromise (IOCs) linked to the BTMOB Remote Access Trojan (RAT), which is known for establishing persistent remote access and exfiltrating sensitive data. A SOC team should proactively search for these IOCs within their Azure Sentinel environment to identify early-stage infections that may evade standard signature-based detections, thereby preventing potential lateral movement and data breaches before they escalate.

IOC Summary

Malware Family: BTMOB RAT Total IOCs: 2 IOC Types: ip:port

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - BTMOB RAT
let malicious_ips = dynamic(["43.240.31.186", "43.240.31.244"]);
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(["43.240.31.186", "43.240.31.244"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — BTMOB RAT

False Positive Guidance

Here are 4 specific false positive scenarios for the ThreatFox: BTMOB RAT IOCs detection rule, including targeted filters and exclusions suitable for an enterprise environment:

• Scenario: Endpoint Protection Scanning of Quarantine Archives

  • Context: Enterprise antivirus solutions (e.g., Microsoft Defender for Endpoint or CrowdStrike Falcon) frequently scan the contents of their own quarantine folders. If a previously detected BTMOB RAT sample was quarantined but not immediately deleted, the AV engine may re-scan the archived file hash, triggering the IOC match as an active threat rather than a historical record.
  • Filter/Exclusion: Exclude processes originating from known EDR agents (e.g., MsMpEng.exe, csfalcon.exe) when they access paths containing “Quarantine,” “Archive,” or “Backup” in the directory name. Additionally, filter out alerts where the file age is greater than 30 days and the process parent is an AV service.

• Scenario: Scheduled Security Compliance Scans

  • Context: Automated compliance tools (such as Tenable Nessus, Qualys, or custom PowerShell scripts) often run nightly to validate endpoint configurations against threat intelligence feeds. These tools may download or reference IOC lists containing BTMOB signatures for verification purposes, causing the detection logic to flag the scan tool itself as a potential carrier of the RAT.
  • Filter/Exclusion: Create an exclusion rule based on the parent process name of scheduled tasks (e.g., Taskeng.exe running scripts named “ComplianceCheck” or “ThreatFeedSync”). Filter out alerts where the source IP belongs to internal security management subnets and the event timestamp aligns with known maintenance windows (e.g., 02:00–04:00 local time).

• Scenario: Software Deployment via Configuration Management *