Suspicious SharePoint Webshell File Creation in LAYOUTS Directory via ToolShell (via file_event)

ATT&CK techniques

Persistence

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1505.003Web Shell
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects creation of known ToolShell webshell and key harvester aspx files inside the SharePoint LAYOUTS directory. These filenames are associated with post exploitation of CVE-2025-53770 and related SharePoint flaws.

Reporting behind it

Related detections9 linkedT1505.003 — drag to rearrange

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Suspicious SharePoint Webshell File Creation in LAYOUTS Directory via ToolShell (via file_event)

Pivot detection · T1505.003 · 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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