Accessed files shared by temporary external user
This detection identifies when an external user is added to a Team or Teams chat and shares a file which is accessed by many users (>10) and the users is removed within short period of time. This might be an…
Description
This detection identifies when an external user is added to a Team or Teams chat and shares a file which is accessed by many users (>10) and the users is removed within short period of time. This might be an indicator of suspicious activity.
Detection logic
Detection requirements
- Platform
- Identity ProviderLinuxmacOSOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source product
- office365
- Log source service
- officeactivity_sharepointofficeactivity_teams
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
No references are available for this detection.
From the source
- At source
- Open at source
- Upstream identifier
- bff058b2-500e-4ae5-bb49-a5b1423cbd5b
- Tagged by the source as
- InitialAccess
Licence
- Published under
- MIT LicenseRead the licence
- Attribution
- Required
- Obtained under
- MITRead the origin licence
Authorship
- Published
- Sep 1, 2026
- Version
- 1