Detection: O365 High Privilege Role Granted

Updated Date: 2024-09-30 ID: e78a1037-4548-4072-bb1b-ad99ae416426 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects when high-privilege roles such as "Exchange Administrator," "SharePoint Administrator," or "Global Administrator" are granted within Office 365. It leverages O365 audit logs to identify events where these roles are assigned to any user or service account. This activity is significant for SOCs as these roles provide extensive permissions, allowing broad access and control over critical resources and data. If confirmed malicious, this could enable attackers to gain significant control over O365 resources, access, modify, or delete critical data, and compromise the overall security and functionality of the O365 environment.

Search

1`o365_management_activity` Operation="Add member to role." Workload=AzureActiveDirectory 
2| eval role_id = mvindex('ModifiedProperties{}.NewValue',2) 
3| eval role_name = mvindex('ModifiedProperties{}.NewValue',1) 
4| where role_id IN ("29232cdf-9323-42fd-ade2-1d097af3e4de", "f28a1f50-f6e7-4571-818b-6a12f2af6b6c", "62e90394-69f5-4237-9190-012177145e10")  
5| stats earliest(_time) as firstTime latest(_time) as lastTime by user Operation ObjectId role_name 
6| `security_content_ctime(firstTime)` 
7| `security_content_ctime(lastTime)` 
8| `o365_high_privilege_role_granted_filter`

Data Source

Name	Platform	Sourcetype	Source
O365 Add member to role.	N/A	`'o365:management:activity'`	`'o365'`

Macros Used

Name	Value
o365_management_activity	`sourcetype=o365:management:activity`
o365_high_privilege_role_granted_filter	`search *`

o365_high_privilege_role_granted_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

HAFNIUM

Lazarus Group

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 Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events.

Known False Positives

Privilege roles may be assigned for legitimate purposes, filter as needed.

Associated Analytic Story

Office 365 Persistence Mechanisms

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
$user$ granted high privilege roles to $ObjectId$	48	80	60

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	`o365`	`o365:management:activity`
Integration	✅ Passing	Dataset	`o365`	`o365:management:activity`

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: 3