Suspicious EKANS Ransomware Payload Dropped to Drive Root (via file_event)

PremiumReviewedSigma · Medium · v1
Product
windows
Category
file_event
Author
HuntRule
Published
2026-09-15
Updated
2026-09-15

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 creation of the file update.exe directly in the root of the C drive, a staging behavior of EKANS ransomware prior to encryption of ICS environments. EKANS drops its payload and ransom note to the drive root and user desktop before terminating industrial and database processes. Writing an executable named update.exe to the drive root is highly unusual and warrants immediate investigation.

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Rhysida Ransomware Encrypted File Extension Created
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Rhysida Ransomware Note CriticalBreachDetected.pdf Created
Possible Akira Ransomware Note or Encrypted Extension Creation
Suspicious EKANS Ransomware Payload Dropped to Drive Root (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.