Detection: Azure AD Global Administrator Role Assigned

Updated Date: 2024-09-30 ID: 825fed20-309d-4fd1-8aaf-cd49c1bb093c Author: Gowthamaraj Rajendran, Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the assignment of the Azure AD Global Administrator role to a user. It leverages Azure Active Directory AuditLogs to identify when the "Add member to role" operation includes the "Global Administrator" role. This activity is significant because the Global Administrator role grants extensive access to data, resources, and settings, similar to a Domain Administrator in traditional AD environments. If confirmed malicious, this could allow an attacker to establish persistence, escalate privileges, and potentially gain control over Azure resources, posing a severe security risk.

1`azure_monitor_aad`  operationName="Add member to role"  properties.targetResources{}.modifiedProperties{}.newValue="\"Global 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_global_administrator_role_assigned_filter`

Data Source

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

Macros Used

Name Value
azure_monitor_aad sourcetype=azure:monitor:aad
azure_ad_global_administrator_role_assigned_filter search *
azure_ad_global_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
T1098.003 Additional Cloud Roles Persistence
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
LAPSUS$
Scattered Spider

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 through an EventHub. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLogs log category.

Known False Positives

Administrators may legitimately assign the Global Administrator role to a user. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Global Administrator Role assigned for User $user$ initiated by $initiatedBy$ 72 80 90
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: 6