Malicious Python Execution from Hidden .pyp Directory in Lazarus InvisibleFerret Chain (via process_creation)

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-09-21
Updated
2026-09-21

ATT&CK techniques

Execution
  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. C2

  12. Exfiltration

  13. Impact

What it detects

This rule detects the Python interpreter running from a hidden .pyp folder inside a user profile, the staging location used by the Lazarus BeaverTail and InvisibleFerret campaign to launch its backdoor and stealer components. The dot-prefixed directory hides a private Python runtime that then executes payloads such as the .sysinfo module. Running python from such a concealed per-user path is not legitimate.

Related detections9 linkedT1059.007 — drag to rearrange
Suspicious Script Host Launching PowerShell from Fattura Named JScript File (via process_creation)
Suspicious Double-Extension PDF JavaScript Lure via WScript (via process_creation)
Suspicious Script Host Spawning PowerShell from Fake Browser Update JS
Suspicious MMC Console Spawning Script Interpreter via GrimResource
Suspicious Script Host Spawning PowerShell via Process Creation
Malicious Node.js Execution of Hidden .claude Setup Script
Suspicious PowerShell Spawned by cscript in Script Chain
Suspicious npm Postinstall Node Execution From Fixtures Path (BeaverTail OtterCookie)
Suspicious Script Host Execution of Decoy-Named JavaScript Dropper (PS1Bot)
Malicious Python Execution from Hidden .pyp Directory in Lazarus InvisibleFerret Chain (via process_creation)
Pivot detection · T1059.007 · 9 related

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