huntrule

Windows NTLM brute force targeting workstation/device names

Alerts on NTLM EventID 8004 when WorkstationName equals common spoofed client names used in brute force attempts.

FreeReviewedSigma · Medium · v2
Product
windows
Service
ntlm
Author
Jerry Shockley '@jsh0x' (SigmaHQ), DRL 1.1
Published
2022-02-02
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Cred Access

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags NTLM authentication events (EventID 8004) where the workstation name matches a set of common tool-spoofed device names. Attackers often brute-force credentials by presenting predictable or reused workstation identifiers to their targets. The detection relies on Microsoft-Windows-NTLM/Operational telemetry, specifically the WorkstationName field captured with the NTLM event.

Reporting behind it

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Windows NTLM brute force targeting workstation/device names
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Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.