Suspicious User State Changed From Guest To Member (via auditlogs)

title: Suspicious User State Changed From Guest To Member (via auditlogs)
id: b2ab0904-b914-5dd7-95e1-c577c39a3f12
status: stable
description: This rule detects the change of user type from "Guest" to "Member" for potential elevation of privilege.
references:
    - https://attack.mitre.org/techniques/T1078/004/
    - https://learn.microsoft.com/en-gb/entra/architecture/security-operations-user-accounts#monitoring-external-user-sign-ins
author: Huntrule Team
date: 2026-03-13
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:
    - Unknown
level: medium