huntrule

PowerShell Storing an Encoded Payload in the Registry (via process_creation)

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-09-03
Updated
2026-09-03
AnalysisDetection

ATT&CK techniques

Persistence → Defense Evasion

  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

  14. Impact

What it detects

This rule detects PowerShell writing a base64 or byte-array value into an HKCU registry key, the fileless persistence and staging behavior seen in Solarmarker and Yellow Cockatoo intrusions. Storing an encoded payload in the registry is a defense-evasion and persistence technique tracked in the Red Canary Threat Detection Report. Detecting this write surfaces a fileless payload being cached for later execution.

Reporting behind it

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Suspicious Deletion of Terminal Server Client History via reg by UNC1549
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PowerShell Storing an Encoded Payload in the Registry (via process_creation)
Pivot detection · T1112 · 9 related

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