Suspicious File Download via Certutil URLCache

PremiumReviewedSigma · Medium · v1
Category
process_creation
Author
HuntRule
Published
2026-07-02
Updated
2026-08-28

ATT&CK techniques

Execution → C2
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Persistence

  5. Priv Esc

  6. Defense Evasion

  7. Cred Access

  8. Discovery

  9. Lateral Movement

  10. Collection

  11. Exfiltration

  12. Impact

What it detects

This rule detects certutil being used with its url cache download flags which the ALPHV intrusion leveraged as a living off the land downloader to stage tooling and this matters because certutil is a signed system binary frequently abused to retrieve remote payloads and its download flags rarely appear in legitimate certificate operations.

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Suspicious File Download via Certutil URLCache
Pivot detection · T1105 · 9 related

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