huntrule

Suspicious SharePoint Worker Process Spawning Command Interpreter via ToolShell

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-09-11
Updated
2026-09-11
AnalysisDetection

ATT&CK techniques

Initial Access → 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 the IIS worker process w3wp.exe spawning a command interpreter such as cmd.exe or PowerShell on a SharePoint server. This behavior is associated with ToolShell exploitation of SharePoint (CVE-2025-53770) leading to remote code execution and webshell deployment. Command interpreter execution under the SharePoint worker process indicates active exploitation and hands-on-keyboard activity.

Reporting behind it

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Malicious SharePoint w3wp Spawning Command Shell and PowerShell
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Malicious PowerShell UrlDecode Payload Spawned by SQL Server after FortiClient EMS Exploitation
Malicious IIS w3wp Worker Spawning Command Interpreter via SharePoint Web Shell
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Suspicious SharePoint Worker Process Spawning Command Interpreter via ToolShell
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.