Suspicious Payload Download to Temp Masquerading as System32 File (via process_creation)

PremiumReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-06-08
Updated
2026-08-28

ATT&CK techniques

Defense Evasion → C2
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Cred Access

  8. Discovery

  9. Lateral Movement

  10. Collection

  11. Exfiltration

  12. Impact

What it detects

This rule detects PowerShell using Invoke-WebRequest to save a payload into the temp directory under a system32 style filename. OneNote delivered malware wrote files such as system32.exe and system32.bat into the user temp path to blend in before launching them.

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Suspicious Payload Download to Temp Masquerading as System32 File (via process_creation)
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.