M365 Exchange Add-FederatedDomain Success: New Federated Domain Created

Alerts on successful Exchange addition of a new federated domain via Add-FederatedDomain.

FreeReviewedSigma · Medium · v4
Product
m365
Service
exchange
Author
Splunk Threat Research Team (original rule), '@ionsor (rule)' (SigmaHQ), DRL 1.1
Published
2022-02-08
Updated
2026-07-31
title: "M365 Exchange Add-FederatedDomain Success: New Federated Domain Created"
id: 482daa67-a439-499a-a313-96e2e5ea09d9
related:
  - id: 58f88172-a73d-442b-94c9-95eaed3cbb36
    type: similar
  - id: 42127bdd-9133-474f-a6f1-97b6c08a4339
    type: derived
status: test
description: This rule identifies successful creation of a new federated domain in Microsoft 365 via Exchange PowerShell, specifically the Add-FederatedDomain operation. Adding a federated domain can enable authentication redirection or federated identity abuse, which attackers may use to persist access using external identity providers. It relies on Exchange telemetry that records eventSource, eventName, and operation status.
references:
  - https://www.fireeye.com/content/dam/fireeye-www/blog/pdfs/wp-m-unc2452-2021-000343-01.pdf
  - https://us-cert.cisa.gov/ncas/alerts/aa21-008a
  - https://www.splunk.com/en_us/blog/security/a-golden-saml-journey-solarwinds-continued.html
  - https://www.sygnia.co/golden-saml-advisory
  - https://o365blog.com/post/aadbackdoor/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/m365/exchange/microsoft365_new_federated_domain_added_exchange.yml
author: Splunk Threat Research Team (original rule), '@ionsor (rule)', Huntrule Team
date: 2022-02-08
tags:
  - attack.persistence
  - attack.t1136.003
logsource:
  service: exchange
  product: m365
detection:
  selection:
    eventSource: Exchange
    eventName: Add-FederatedDomain
    status: success
  condition: selection
falsepositives:
  - The creation of a new Federated domain is not necessarily malicious, however these events need to be followed closely, as it may indicate federated credential abuse or backdoor via federated identities at a similar or different cloud provider.
level: medium
license: DRL-1.1