Detection: Azure AD Privileged Authentication Administrator Role Assigned

Updated Date: 2024-05-20 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.

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 Supported App
Azure Active Directory Add member to role Azure icon Azure 'azure:monitor:aad' 'Azure AD' N/A

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
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
APT29
APT41
APT5
Dragonfly
FIN13
GALLIUM
Ke3chang
Threat Group-3390
Wizard Spider
menuPass

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

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
The privileged Azure AD role Privileged Authentication Administrator was assigned for User $user$ initiated by $initiatedBy$ 50 100 50
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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: 3