Detection: Azure AD Privileged Authentication Administrator Role Assigned

Updated Date: 2024-11-14 ID: a7da845d-6fae-41cf-b823-6c0b8c55814a Author: Mauricio Velazco, Gowthamaraj Rajendran, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the assignment of the Privileged Authentication Administrator role to an Azure AD user. It leverages Azure Active Directory audit logs to identify when this specific role is assigned. This activity is significant because users in this role can set or reset authentication methods for any user, including those in privileged roles like Global Administrators. If confirmed malicious, an attacker could change credentials and assume the identity and permissions of high-privilege users, potentially leading to unauthorized access to sensitive information and critical configurations.

Search

1`azure_monitor_aad`  "operationName"="Add member to role"  "properties.targetResources{}.modifiedProperties{}.newValue"="\"Privileged Authentication Administrator\"" 
2| rename properties.* as * 
3| rename initiatedBy.user.userPrincipalName as initiatedBy 
4| stats count min(_time) as firstTime max(_time) as lastTime values(user) as user by initiatedBy, result, operationName 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `azure_ad_privileged_authentication_administrator_role_assigned_filter`

Data Source

Name	Platform	Sourcetype	Source
Azure Active Directory Add member to role	Azure	`'azure:monitor:aad'`	`'Azure AD'`

Macros Used

Name	Value
azure_monitor_aad	`sourcetype=azure:monitor:aad`
azure_ad_privileged_authentication_administrator_role_assigned_filter	`search *`

azure_ad_privileged_authentication_administrator_role_assigned_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1003.002	Security Account Manager	Credential Access

Exploitation

DE.CM

CIS 10

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

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

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 AuditLog log category.

Known False Positives

Administrators may legitimately assign the Privileged Authentication Administrator role as part of administrative tasks. Filter as needed.

Associated Analytic Story

Azure Active Directory Privilege Escalation

Risk Based Analytics (RBA)

Risk Message:

The privileged Azure AD role Privileged Authentication Administrator was assigned for User $user$ initiated by $initiatedBy$

Risk Object	Risk Object Type	Risk Score	Threat Objects
initiatedBy	user	50	No Threat Objects
user	user	50	No Threat Objects

References

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: 6