huntrule

Suspicious BadIIS Service Persistence Masquerading as System Services

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-08-11
Updated
2026-08-28
AnalysisDetection

ATT&CK techniques

Persistence → Defense Evasion

  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 detects creation of Windows services under the BadIIS masquerading names Winlogin, FaxService or AudiosService, which imitate legitimate system service names through subtle misspellings. The commodity BadIIS ecosystem installs services under these deceptive names to persist and blend into service inventories. Creation of a service with these typo-squatted names indicates BadIIS persistence.

Reporting behind it

Related detections9 linkedT1543.003 — drag to rearrange
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Suspicious Service Creation Masquerading as FortiGateUpdate (via process_creation)
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Suspicious EACoreServer Masquerading as WindowsUpdate Executable (via process_creation)
Suspicious Stately Taurus Masqueraded Service and Task Persistence via process_creation
Malicious Vulnerable Driver Load for EDR Evasion (via image_load)
Malicious Gelsemium OwlProxy wmipd DLL Load via image_load
Malicious Turla TinyTurla w64time DLL Load via image_load
Malicious APT15 Persistence via Nwsapagent Service or Run Key Registry Value
Suspicious BadIIS Service Persistence Masquerading as System Services
Pivot detection · T1543.003 · 9 related

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