teams 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.

t1098
o365
elastic

Techniques

T1098

Sample rules

Microsoft 365 Teams Guest Access Enabled

source: elastic
technicques:
- T1098

Description

Identifies 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.

Detection logic

event.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