ID | Technique | Tactic |
---|---|---|
T1484 | Domain or Tenant Policy Modification | Defense Evasion |
T1484.002 | Trust Modification | Privilege Escalation |
Detection: Azure AD New Federated Domain Added
Description
The following analytic detects the addition of a new federated domain within an Azure Active Directory tenant. It leverages Azure AD AuditLogs to identify successful "Set domain authentication" operations. This activity is significant as it may indicate the use of the Azure AD identity federation backdoor technique, allowing an adversary to establish persistence. If confirmed malicious, the attacker could impersonate any user, bypassing password and MFA requirements, potentially leading to unauthorized access and control over the Azure AD environment.
Search
1`azure_monitor_aad` operationName="Set domain authentication" "properties.result"=success
2| rename properties.* as *
3| rename targetResources{}.displayName as domain
4| stats count min(_time) as firstTime max(_time) as lastTime by user, domain, result, operationName, src_ip
5| `security_content_ctime(firstTime)`
6| `security_content_ctime(lastTime)`
7| `azure_ad_new_federated_domain_added_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Azure Active Directory Set domain authentication | Azure | 'azure:monitor:aad' |
'Azure AD' |
N/A |
Macros Used
Name | Value |
---|---|
azure_monitor_aad | sourcetype=azure:monitor:aad |
azure_ad_new_federated_domain_added_filter | search * |
azure_ad_new_federated_domain_added_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
Implementation
You must install the latest version of Splunk Add-on for Microsoft Cloud Services from Splunkbase (https://splunkbase.splunk.com/app/3110/#/details). You must be ingesting Azure Active Directory events into your Splunk environment. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLogs log category.
Known False Positives
In most organizations, domain federation settings will be updated infrequently. Filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A new federated domain, $domain$ , was added by $user$ | 81 | 90 | 90 |
References
-
https://www.inversecos.com/2021/11/how-to-detect-azure-active-directory.html
-
https://www.mandiant.com/resources/blog/detecting-microsoft-365-azure-active-directory-backdoors
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | Azure AD |
azure:monitor:aad |
Integration | ✅ Passing | Dataset | Azure AD |
azure:monitor:aad |
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
Source: GitHub | Version: 4