Azure AD Global Administrator Role Assigned

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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.

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2024-05-29
• Author: Gowthamaraj Rajendran, Mauricio Velazco, Splunk
• ID: 825fed20-309d-4fd1-8aaf-cd49c1bb093c

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1098.003	Additional Cloud Roles	Persistence, Privilege Escalation

Kill Chain Phase

• Installation
• Exploitation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`azure_monitor_aad`  operationName="Add member to role"  properties.targetResources{}.modifiedProperties{}.newValue="\"Global Administrator\"" 
| rename properties.* as * 
| rename initiatedBy.user.userPrincipalName as initiatedBy 
| stats count min(_time) as firstTime max(_time) as lastTime values(user) as user by initiatedBy, result, operationName 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_global_administrator_role_assigned_filter`

Macros

The SPL above uses the following Macros:

• azure_monitor_aad
• security_content_ctime

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

Required fields

List of fields required to use this analytic.

• _time
• user
• properties.targetResources{}.type
• properties.initiatedBy.user.userPrincipalName
• properties.result

How To Implement

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

• Azure Active Directory Persistence
• Azure Active Directory Privilege Escalation

RBA

Risk Score	Impact	Confidence	Message
72.0	80	90	Global Administrator Role assigned for User $user$ initiated by $initiatedBy$

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://o365blog.com/post/admin/
• https://adsecurity.org/?p=4277
• https://www.mandiant.com/resources/detecting-microsoft-365-azure-active-directory-backdoors
• https://docs.microsoft.com/en-us/azure/active-directory/roles/security-planning
• https://docs.microsoft.com/en-us/azure/role-based-access-control/elevate-access-global-admin
• https://attack.mitre.org/techniques/T1098/003/

Test Dataset

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 | version: 5