Malicious NailaoLocker Ransom Note and Encrypted File Creation (via file_event)

PremiumReviewedSigma · High · v1
Product
windows
Category
file_event
Author
HuntRule
Published
2026-09-24
Updated
2026-09-24

ATT&CK techniques

Impact
  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

What it detects

This rule detects file system artifacts of NailaoLocker which writes the ransom note unlock_please_view_this_file.html and appends the .locked extension to encrypted files. The locker also drops a lock.log progress file under ProgramData. Creation of these named artifacts indicates active encryption.

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Malicious BlackSuit Ransomware Execution via Process Creation
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Malicious NailaoLocker Ransom Note and Encrypted File Creation (via file_event)
Pivot detection · T1486 · 9 related

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