User State Changed From Guest To Member

Title: User State Changed From Guest To Member
Status: test
Description:Detects the change of user type from "Guest" to "Member" for potential elevation of privilege.
References:
  -https://learn.microsoft.com/en-gb/entra/architecture/security-operations-user-accounts#monitoring-external-user-sign-ins
Author: MikeDuddington, '@dudders1'
Date: 2022-06-30
modified:None
Tags:

• -'attack.persistence'
• -'attack.privilege-escalation'
• -'attack.initial-access'
• -'attack.stealth'
• -'attack.t1078.004'

Logsource:

• product: azure
• service: auditlogs

Detection:
  selection:
    Category: 'UserManagement'
    OperationName: 'Update user'
    properties.message: '"displayName":"UserType","oldValue":"[\"Guest\"]","newValue":"[\"Member\"]"'
  condition:selection
Falsepositives:
  -If this was approved by System Administrator.
Level: medium