Microsoft 365 Teams Guest Access Enabled
editMicrosoft 365 Teams Guest Access Enabled
editIdentifies when guest access is enabled in Microsoft Teams. Guest access in Teams allows people outside the organization to access teams and channels. An adversary may enable guest access to maintain persistence in an environment.
Rule type: query
Rule indices:
- filebeat-*
- logs-o365*
Severity: medium
Risk score: 47
Runs every: 5 minutes
Searches indices from: now-30m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Cloud
- Microsoft 365
- Continuous Monitoring
- SecOps
- Configuration Audit
Version: 4 (version history)
Added (Elastic Stack release): 7.11.0
Last modified (Elastic Stack release): 7.13.0
Rule authors: Elastic
Rule license: Elastic License v2
Potential false positives
editTeams guest access may be enabled by a system or network administrator. Verify that the configuration change was expected. Exceptions can be added to this rule to filter expected behavior.
Investigation guide
editConfig
The Microsoft 365 Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.
Rule query
editevent.dataset:o365.audit and event.provider:(SkypeForBusiness or MicrosoftTeams) and event.category:web and event.action:"Set- CsTeamsClientConfiguration" and o365.audit.Parameters.AllowGuestUser:True and event.outcome:success
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
-
Technique:
- Name: Account Manipulation
- ID: T1098
- Reference URL: https://attack.mitre.org/techniques/T1098/
Rule version history
edit- Version 4 (7.13.0 release)
-
- Formatting only
- Version 3 (7.12.0 release)
-
- Formatting only
- Version 2 (7.11.2 release)
-
- Formatting only