Azure AD New Custom Domain Added
The following analytic detects the addition of a new custom domain within an Azure Active Directory (AD) tenant. It leverages Azure AD AuditLogs to identify successful "Add unverified domain" operations. This…
Description
The following analytic detects the addition of a new custom domain within an Azure Active Directory (AD) tenant. It leverages Azure AD AuditLogs to identify successful "Add unverified domain" operations. This activity is significant as it may indicate an adversary attempting to establish persistence by setting up identity federation backdoors, allowing them to impersonate users and bypass authentication mechanisms. If confirmed malicious, this could enable attackers to gain unauthorized access, escalate privileges, and maintain long-term access to the Azure AD environment, posing a severe security risk.
Detection logic
Detection requirements
- Platform
- Identity ProviderWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- azure_active_directory_add_unverified_domain
Known benign triggers
- In most organizations, new customm domains will be updated infrequently. Filter as needed.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| attack.mitre.org/techniques/T1484/002/ | 3 |
| docs.microsoft.com/en-us/azure/active-directory/enterprise-users/domains-manage | Only this detection cites it |
| o365blog.com/post/federation-vulnerability/ | 3 |
| www.inversecos.com/2021/11/how-to-detect-azure-active-directory.html | 3 |
| www.mandiant.com/resources/blog/detecting-microsoft-365-azure-active-directory-backdoors | 3 |
| www.mandiant.com/resources/remediation-and-hardening-strategies-microsoft-365-defend-against-apt29-v13 | 3 |
From the source
- At source
- Open at source
- Upstream identifier
- 30c47f45-dd6a-4720-9963-0bca6c8686ef
- Tagged by the source as
- Azure Active Directory PersistenceAzure Active DirectorycloudSplunk CloudSplunk EnterpriseSplunk Enterprise Securitythreat
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Published
- Aug 26, 2026
- Version
- 1