Azure AD Privileged Role Assigned

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Description

The following analytic identifies the assignment of sensitive and privileged Azure Active Directory roles to an Azure AD user. Adversaries and red teams alike may assign these roles to a compromised account to establish Persistence in an Azure AD environment.

• Type: TTP

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

• Last Updated: 2023-12-20
• Author: Mauricio Velazco, Gowthamaraj Rajendran, Splunk
• ID: a28f0bc3-3400-4a6e-a2da-89b9e95f0d2a

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1098	Account Manipulation	Persistence, Privilege Escalation

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" 
| rename properties.*  as * 
| rename initiatedBy.user.userPrincipalName as initiatedBy 
| rename targetResources{}.modifiedProperties{}.newValue  as roles 
| eval role=mvindex(roles,1) 
| lookup privileged_azure_ad_roles azureadrole AS role OUTPUT isprvilegedadrole description 
| search isprvilegedadrole = True 
| stats count min(_time) as firstTime max(_time) as lastTime values(user) as user by initiatedBy, result, operationName, role, description 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_privileged_role_assigned_filter`

Macros

The SPL above uses the following Macros:

• azure_monitor_aad
• security_content_ctime

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

Lookups

The SPL above uses the following Lookups:

• privileged_azure_ad_roles with data

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. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLog log category.

Known False Positives

Administrators will legitimately assign the privileged roles users as part of administrative tasks. Filter as needed.

Associated Analytic Story

• Azure Active Directory Persistence
• NOBELIUM Group

RBA

Risk Score	Impact	Confidence	Message
63.0	70	90	A privileged Azure AD role was 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://docs.microsoft.com/en-us/azure/active-directory/roles/concept-understand-roles
• https://docs.microsoft.com/en-us/azure/active-directory/roles/permissions-reference
• 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://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

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