huntrule

Malicious Office Application Spawning PowerShell with Encoded Command

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-10-04
Updated
2026-10-04
AnalysisDetection

ATT&CK techniques

Execution

  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 a Microsoft Office application such as winword.exe or excel.exe spawning cmd.exe or powershell.exe with an EncodedCommand argument, a hallmark of malicious document execution delivering an obfuscated payload. Office productivity apps do not normally launch encoded PowerShell. This parent-child chain indicates user-driven macro or exploit execution leading to code execution.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange
Suspicious PowerShell String Concatenation Obfuscation for Batch Extension via LNK (via process_creation)
Suspicious Encoded JScript Execution via WScript (via process_creation)
Suspicious Batch Fake Installer Spawning PowerShell Downloader via OXLoader
Malicious Web Browser Spawning Command or Script Interpreter
Suspicious Python Inline Exec Execution in STARKVEIL Chain
Malicious TELEPUZ ClickFix Stager via Hidden PowerShell Grab Endpoint
Suspicious Hidden PowerShell Retrieving VBScript from mcdir.me by Millenium RAT (via process_creation)
Suspicious Command in RunMRU Registry Indicating ClickFix Execution (via registry_set)
Suspicious Edge Update Setup Spawning PowerShell via ClearFake
Malicious Office Application Spawning PowerShell with Encoded Command
Pivot detection · T1059.001 · 9 related

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