Azure Entra: Guest User Invitation Failed When Initiated by Non-Privileged User
Identifies failed guest user invitations in Azure audit logs when the inviter lacks required permissions.
- Product
- azure
- Service
- auditlogs
- Author
- Mark Morowczynski '@markmorow', Yochana Henderson, '@Yochana-H' (SigmaHQ), DRL 1.1
- Published
- 2022-08-10
- Updated
- 2026-07-31
ATT&CK techniques
Initial Access → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule catches failed attempts to invite an external/guest user where the action is issued by an account that lacks permission to invite guests. Attackers may probe or attempt privilege escalation by repeatedly triggering guest invitation operations until a success condition is met. The detection relies on Azure audit log events that include the invitation message and a failure status.
Reporting behind it
Changelog
v5- v5Candidate ingested via manual entry.2026-07-31
- v4Candidate ingested via manual entry.2026-07-31
- v3Candidate ingested via manual entry.2026-07-31
- v2Candidate ingested via manual entry.2026-07-31
- v1No 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.
title: "Azure Entra: Guest User Invitation Failed When Initiated by Non-Privileged User"
id: 197d889d-d287-430d-bfa1-50c56d5b2d61
status: test
description: This rule catches failed attempts to invite an external/guest user where the action is issued by an account that lacks permission to invite guests. Attackers may probe or attempt privilege escalation by repeatedly triggering guest invitation operations until a success condition is met. The detection relies on Azure audit log events that include the invitation message and a failure status.
references:
- https://learn.microsoft.com/en-us/entra/architecture/security-operations-privileged-accounts#things-to-monitor
- https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/audit_logs/azure_guest_invite_failure.yml
author: Mark Morowczynski '@markmorow', Yochana Henderson, '@Yochana-H', Huntrule Team
date: 2022-08-10
tags:
- attack.privilege-escalation
- attack.initial-access
- attack.persistence
- attack.stealth
- attack.t1078.004
logsource:
product: azure
service: auditlogs
detection:
selection:
properties.message: Invite external user
Status: failure
condition: selection
falsepositives:
- A non malicious user is unaware of the proper process
level: medium
license: DRL-1.1
related:
- id: 0b4b72e3-4c53-4d5b-b198-2c58cfef39a9
type: derived