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Windows Security Event LSASS Process Access by Non-Computer Account

Alerts on suspicious LSASS access attempts (4663/4656) targeting lsass.exe by non-system processes using flagged access masks.

FreeReviewedSigma · Medium · v4
Product
windows
Service
security
Author
Roberto Rodriguez @Cyb3rWard0g (SigmaHQ), DRL 1.1
Published
2019-06-20
Updated
2026-10-20
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 Windows Security events where a process other than a computer account attempts to access lsass.exe with specific AccessMask values. Credential dumping tools commonly read LSASS memory, so unexpected LSASS access is a high-signal indicator of potential credential access activity. The detection relies on event telemetry for file/process access activity (EventID 4656/4663) and the requesting subject identity, filtering out common system/whitelisted process contexts.

Reporting behind it

Related detections9 linkedT1003.001 — drag to rearrange
Malicious Mimikatz Credential Dumping via Command Line Arguments
Malicious Credential Extraction via Volatility Memory Analysis (via process_creation)
Suspicious Physical Memory Acquisition via WinPmem (via process_creation)
Malicious LSASS Credential Dump via Rundll32 Comsvcs MiniDump via Process Creation (via process_creation)
Suspicious LSASS Credential Access via PowerShell (via process_creation)
Suspicious LSASS Memory Dump via Task Manager After Ivanti Exploitation
Suspicious ProcDump LSASS Memory Dump via process_creation
Malicious Mimikatz Credential Dump Log File Creation (via file_event)
Malicious WDigest UseLogonCredential Enabled for Cleartext Credential Theft (via registry_set)
Windows Security Event LSASS Process Access by Non-Computer Account
Pivot detection · T1003.001 · 9 related

Changelog

v4
  1. v4
    Candidate ingested via manual entry.2026-10-20
  2. v2
    Candidate ingested via manual entry.2026-07-31
  3. 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.