Detection: Azure AD Global Administrator Role Assigned

Updated Date: 2024-05-29 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.

Search

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

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: 5