M365 Copilot Session Origin Anomalies
Detects M365 Copilot users accessing from multiple geographic locations to identify potential account compromise, credential sharing, or impossible travel patterns. The detection aggregates M365 Copilot Graph API…
Description
Detects M365 Copilot users accessing from multiple geographic locations to identify potential account compromise, credential sharing, or impossible travel patterns. The detection aggregates M365 Copilot Graph API events per user, calculating distinct cities and countries accessed, unique IP addresses, and the observation timeframe to compute a locations-per-day metric that measures geographic mobility. Users accessing Copilot from more than one city (cities_count > 1) are flagged and sorted by country and city diversity, surfacing accounts exhibiting anomalous geographic patterns that suggest compromised credentials being used from distributed locations or simultaneous access from impossible travel distances.
Detection logic
Detection requirements
- Platform
- ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- m365_copilot_graph_api
Known benign triggers
- Legitimate business travelers, remote workers using VPNs, users with corporate offices in multiple locations, or employees accessing Copilot during international travel may trigger false positives.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| www.splunk.com/en_us/blog/artificial-intelligence/m365-copilot-log-analysis-splunk.html | 8 |
From the source
- At source
- Open at source
- Upstream identifier
- 0caf1c1c-0fba-401e-8ec7-f07cfdeee75b
- Tagged by the source as
- Suspicious Microsoft 365 Copilot ActivitiesWeb ApplicationapplicationSplunk CloudSplunk EnterpriseSplunk Enterprise Securityaccess
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1