Malicious SharePoint ToolShell Exploitation via ToolPane Endpoint

ATT&CK techniques

Initial Access

Recon
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a POST request to the SharePoint ToolPane endpoint in edit mode with a referer set to the SignOut page, the exact exploitation pattern of the ToolShell on-premises SharePoint vulnerabilities. This unauthenticated request chain is used to forge ViewState and achieve remote code execution and should be treated as active exploitation.

Reporting behind it

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Malicious SharePoint ToolShell Exploitation via ToolPane Endpoint

Pivot detection · T1190 · 9 related

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

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