ThreatFox: Havoc IOCs

Hunt Hypothesis

This detection rule identifies adversary activity linked to the Havoc post-exploitation toolkit by monitoring specific indicators of compromise such as unique process execution and network connections. Proactively hunting for these signals in Azure Sentinel is critical because Havoc’s modular design allows attackers to establish persistent footholds, enabling early disruption before lateral movement or data exfiltration occurs.

IOC Summary

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

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - Havoc
let malicious_ips = dynamic(["43.134.169.103", "45.61.176.146"]);
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(["43.134.169.103", "45.61.176.146"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — Havoc

False Positive Guidance

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

• Scenario 1: Scheduled Vulnerability Scanning via Tenable Nessus

  • Context: The nightly vulnerability scan job configured in Tenable Nessus connects to the Havoc threat intelligence feed URL (often hosted on a public IP or specific domain like threatfox.io) to update its local signature database. This network connection matches the Havoc IOCs, triggering an alert despite being a routine maintenance task.
  • Filter/Exclusion: Create an exclusion rule for traffic originating from the Nessus Manager Service (Process Name: nessusd.exe or java.exe) on the specific scanner server IP range (10.x.x.x). Additionally, exclude the destination port 443 if the connection is strictly to the known ThreatFox update endpoint.

• Scenario 2: Automated SIEM Enrichment via Splunk Add-on

  • Context: The enterprise Splunk Enterprise Security (ES) instance runs a scheduled job every hour to pull threat intelligence data from the ThreatFox API using the Havoc module. This background process (splunkd.exe) initiates outbound HTTPS connections that match the Havoc IOCs, generating alerts for what is essentially an internal enrichment workflow.
  • Filter/Exclusion: Implement a filter to suppress alerts where the source process is splunkd.exe and the destination domain matches the ThreatFox API endpoint (api.threatfox.io). Alternatively, add the Splunk indexer IP addresses to the “Trusted Source” list for this specific rule.

• Scenario 3: Admin Manual Threat Research using Microsoft Defender

  • Context: A SOC analyst manually investigates a potential incident by querying the