Microsoft 365 Teams Custom Application Interaction Allowededit

Identifies when custom applications are allowed in Microsoft Teams. If an organization requires applications other than those available in the Teams app store, custom applications can be developed as packages and uploaded. An adversary may abuse this behavior to establish 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: 2 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 7.11.2

Rule authors: Elastic

Rule license: Elastic License

Potential false positivesedit

Custom applications may be allowed 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 guideedit

The Microsoft 365 Fleet integration or Filebeat module must be enabled to use this rule.

Rule queryedit

event.dataset:o365.audit and event.provider:MicrosoftTeams and
event.category:web and event.action:TeamsTenantSettingChanged and
o365.audit.Name:"Allow sideloading and interaction of custom apps" and
o365.audit.NewValue:True and event.outcome:success

Rule version historyedit

Version 2 (7.11.2 release)
  • Formatting only