Windows SharePoint ToolPane Endpoint Exploitation Attempt

name: Windows SharePoint ToolPane Endpoint Exploitation Attempt
id: 508b2649-3a1e-4a4c-ba9d-3cc05e1a1b70
version: 5
creation_date: '2025-07-20'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects potential exploitation attempts against Microsoft SharePoint Server vulnerability CVE-2025-53770, also known as "ToolShell". This detection monitors for POST requests to the ToolPane.aspx endpoint with specific DisplayMode parameter, which is a key indicator of the exploit. This vulnerability allows unauthenticated remote code execution on affected SharePoint servers, enabling attackers to fully access SharePoint content, file systems, internal configurations, and execute code over the network.
data_source:
    - Suricata
search: |-
    | tstats count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Web
      WHERE Web.url="*/_layouts/15/ToolPane.aspx*"
        AND
        Web.url="*DisplayMode=Edit*" Web.http_method=POST
      BY Web.http_user_agent, Web.status, Web.http_method,
         Web.url, Web.url_length, Web.src,
         Web.dest, sourcetype
    | `drop_dm_object_name("Web")`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_sharepoint_toolpane_endpoint_exploitation_attempt_filter`
how_to_implement: This detection requires the Web datamodel to be populated from a supported Technology Add-On like Splunk for Microsoft SharePoint or web proxy logs that capture SharePoint traffic. Configure AMSI integration in SharePoint and deploy Microsoft Defender AV on all SharePoint servers as recommended by Microsoft to provide additional protection.
known_false_positives: Limited false positives are expected as legitimate use of the ToolPane.aspx endpoint with DisplayMode=Edit parameter in POST requests is uncommon. However, some SharePoint administration activities might trigger this detection. Verify against known administrator IPs and activity patterns.
references:
    - https://research.eye.security/sharepoint-under-siege/
    - https://cybersecuritynews.com/sharepoint-0-day-rce-vulnerability-exploited/
    - https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
    - https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770
    - https://splunkbase.splunk.com/app/3185
finding:
    title: Potential SharePoint ToolPane exploitation (CVE-2025-53770) detected from $src$ targeting $dest$
    entity:
        field: dest
        type: system
        score: 50
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - Microsoft SharePoint Vulnerabilities
asset_type: Web Server
cve:
    - CVE-2025-53770
mitre_attack_id:
    - T1190
    - T1505.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: web
security_domain: network