ThreatFox: BeaverTail IOCs

Hunt Hypothesis

This hunt targets BeaverTail malware activity characterized by encrypted command-and-control channels and lateral movement using compromised credentials, which often evade standard perimeter defenses. Proactively hunting for these IOCs in Azure Sentinel is critical to identify early-stage data exfiltration attempts and prevent the malware from establishing persistent footholds within the network.

IOC Summary

Malware Family: BeaverTail Total IOCs: 4 IOC Types: url

KQL: Url Hunt

// Hunt for access to known malicious URLs
// Source: ThreatFox - BeaverTail
let malicious_urls = dynamic(["https://apigoogle-ashen.vercel.app/api/settings/linux", "https://ipcheck-vm.vercel.app/api", "https://checking-ip-eight.vercel.app/api/ip-check-encrypted/3aeb34a37", "https://www.jsonkeeper.com/b/HTCVE"]);
UrlClickEvents
| where Url has_any (malicious_urls)
| project Timestamp, AccountUpn, Url, ActionType, IsClickedThrough
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — BeaverTail

False Positive Guidance

• Legitimate Phishing Campaign Testing (EASM/Security Awareness Training)

  • Scenario: Security teams or third-party providers (e.g., KnowBe4, Proofpoint) conduct periodic phishing simulations where users click on malicious-looking URLs that redirect to internal or external tracking servers to verify user behavior. If the redirect chain involves an IP or domain listed in the ThreatFox BeaverTail IOC set, the rule may trigger on the initial HTTP GET request or subsequent C2-like beaconing during the test.
  • Filter/Exclusion: Exclude source IPs belonging to the Security Awareness Training platform or specific user groups designated for “Phishing Test” accounts. Alternatively, create a dynamic tag in the SIEM for “Phishing Sim” events and suppress alerts where the user context matches this tag.

• Scheduled External Backup or Sync Jobs

  • Scenario: Enterprise backup solutions (e.g., Veeam, Commvault) or cloud sync agents (e.g., OneDrive for Business, SharePoint connectors) may establish outbound connections to specific cloud endpoints or staging servers for data exfiltration. If a backup agent is configured to use a non-standard port or a specific IP range that overlaps with BeaverTail C2 indicators, the “unusual outbound traffic” heuristic may flag the regular, encrypted sync traffic as suspicious.
  • Filter/Exclusion: Whitelist the specific service accounts or machine identities (e.g., svc-backup-01) and their associated IP ranges. Ensure the exclusion is scoped to the specific destination ports (e.g., 443, 8443) and source hosts known to run backup agents.

• DevOps CI/CD Pipeline Artifacts and Container Images

  • Scenario: In containerized environments (Kubernetes, Docker), CI/CD pipelines (e.g., Jenkins, GitLab CI) pull base images or dependencies from