Detection: Azure AD PIM Role Assignment Activated

Updated Date: 2024-05-25 ID: 952e80d0-e343-439b-83f4-808c3e6fbf2e Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the activation of an Azure AD Privileged Identity Management (PIM) role. It leverages Azure Active Directory events to identify when a user activates a PIM role assignment, indicated by the "Add member to role completed (PIM activation)" operation. Monitoring this activity is crucial as PIM roles grant elevated privileges, and unauthorized activation could indicate an adversary attempting to gain privileged access. If confirmed malicious, this could lead to unauthorized administrative actions, data breaches, or further compromise of the Azure environment.

Search

1 `azure_monitor_aad` operationName="Add member to role completed (PIM activation)" 
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 values(targetResources{}.displayName) as displayName by initiatedBy, result, operationName 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `azure_ad_pim_role_assignment_activated_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Azure Active Directory	Azure	`'azure:monitor:aad'`	`'Azure AD'`	N/A

Macros Used

Name	Value
azure_monitor_aad	`sourcetype=azure:monitor:aad`
azure_ad_pim_role_assignment_activated_filter	`search *`

azure_ad_pim_role_assignment_activated_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	Account Manipulation	Persistence
T1098.003	Additional Cloud Roles	Privilege Escalation

KillChainPhase.EXPLOITAITON

KillChainPhase.INSTALLATION

NistCategory.DE_CM

Cis18Value.CIS_10

APT3

APT41

APT5

Dragonfly

FIN13

HAFNIUM

Kimsuky

Lazarus Group

Magic Hound

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

Known False Positives

As part of legitimate administrative behavior, users may activate PIM roles. Filter as needed

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
An Azure AD PIM role assignment was activated by $initiatedBy$ by $user$	35	70	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	`eventhub://researchhub1.servicebus.windows.net/azureadhub;`	`azure:monitor:aad`
Integration	✅ Passing	Dataset	`eventhub://researchhub1.servicebus.windows.net/azureadhub;`	`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: 4