Azure Audit Logs: UserType updated from Guest to Member

Alerts when an Azure user’s UserType is updated from Guest to Member, indicating potential privilege elevation.

FreeReviewedSigma · Medium · v5

Product: azure
Service: auditlogs
Author: MikeDuddington, '@dudders1' (SigmaHQ), DRL 1.1
Published: 2022-06-30
Updated: 2026-07-31

ATT&CK techniques

Initial Access → Defense Evasion

Recon
Resource Dev
Initial Access
- T1078.004Cloud Accounts
Execution
Persistence
- T1078.004Cloud Accounts
Priv Esc
- T1078.004Cloud Accounts
Defense Evasion
- T1078.004Cloud Accounts
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule matches Azure audit log events where a user management operation updates a user’s UserType from "Guest" to "Member". Such a change can enable additional access or privileges, making it relevant for detecting potential elevation of privilege or stealthy permission gains. It relies on UserManagement “Update user” events with a message indicating the old and new UserType values.

Reporting behind it

Related detections9 linkedT1078.004 — drag to rearrange

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Azure Audit Logs: UserType updated from Guest to Member

Pivot detection · T1078.004 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

azure-audit-logs-user-type-changed-from-guest-to-member-8dee7a0d

title: "Azure Audit Logs: UserType updated from Guest to Member"
id: 29ce7a7e-14eb-40f6-b594-3e9464e317f8
status: test
description: This rule matches Azure audit log events where a user management operation updates a user’s UserType from "Guest" to "Member". Such a change can enable additional access or privileges, making it relevant for detecting potential elevation of privilege or stealthy permission gains. It relies on UserManagement “Update user” events with a message indicating the old and new UserType values.
references:
  - https://learn.microsoft.com/en-gb/entra/architecture/security-operations-user-accounts#monitoring-external-user-sign-ins
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/audit_logs/azure_guest_to_member.yml
author: MikeDuddington, '@dudders1', Huntrule Team
date: 2022-06-30
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
license: DRL-1.1
related:
  - id: 8dee7a0d-43fd-4b3c-8cd1-605e189d195e
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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