ThreatFox: BeaverTail IOCs

Hunt Hypothesis

This hypothesis posits that adversaries are actively deploying BeaverTail malware to establish persistence and exfiltrate sensitive data via known indicators of compromise within the Azure environment. The SOC team should proactively hunt for these specific IOCs in Azure Sentinel to rapidly identify early-stage infections before they escalate into broader lateral movement or data breach incidents.

IOC Summary

Malware Family: BeaverTail Total IOCs: 7 IOC Types: sha256_hash, ip:port, domain

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - BeaverTail
let malicious_ips = dynamic(["172.86.123.37"]);
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(["172.86.123.37"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - BeaverTail
let malicious_domains = dynamic(["code-beautify.com", "ipregionchecker.org"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc

KQL: Hash Hunt

// Hunt for files matching known malicious hashes
// Source: ThreatFox - BeaverTail
let malicious_hashes = dynamic(["74009ad71c2f41ebfe6b76358f0224f814f8dca1167a858538b5e8df8a76b881", "017cb09cabd9c909e4fb06e8c668d2f89e472e103eda5230d98761a9f998bdb5", "0e1ae44c555c13b03bdbd72f66c456aaffcdd13887ebe9859d302a63e409c462"]);
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 — BeaverTail

False Positive Guidance

Here are 4 specific false positive scenarios for the ThreatFox: BeaverTail IOCs detection rule in an enterprise environment, along with suggested filters or exclusions:

• Endpoint Detection and Response (EDR) Policy Updates via Microsoft Defender for Endpoint

  • Scenario: The security team pushes a new definition update or policy change to the EDR agent. This process triggers a background service (MsMpEng.exe or DefenderService) that downloads and validates signature files from the vendor’s cloud repository, inadvertently matching one of BeaverTail’s known hash IOCs used for legitimate software distribution.
  • Suggested Filter: Exclude network traffic and file hashes originating specifically from the EDR management console IP range (e.g., 10.20.5.0/24) or exclude processes where the parent process is MsMpEng.exe running under the SYSTEM account with a known digital signature from Microsoft Corporation.

• Scheduled Software Patching via SCCM (System Center Configuration Manager)

  • Scenario: A nightly scheduled job runs to deploy critical security patches across the enterprise using SCCM. During this deployment, the client agent (ccmexec.exe) downloads installer packages that contain BeaverTail-associated IOCs as part of a third-party vendor’s update bundle (e.g., Adobe or Java updates) which are whitelisted by IT but flagged by the threat rule.
  • Suggested Filter: Create an exclusion for file creation events where the InitiatingProcessName is ccmexec.exe and the CommandLine contains the specific SCCM package ID associated with routine patching cycles (e.g., PackageID=ABC123-PATCH).

• Enterprise Email Gateway Scanning by Proofpoint or Mimecast

  • Scenario: The email gateway performs deep content inspection on incoming bulk newsletters or internal announcements. The