Detection: O365 Application Registration Owner Added

Updated Date: 2024-05-11 ID: c068d53f-6aaa-4558-8011-3734df878266 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies instances where a new owner is assigned to an application registration within an Azure AD and Office 365 tenant. It leverages O365 audit logs, specifically events related to changes in owner assignments within the AzureActiveDirectory workload. This activity is significant because assigning a new owner to an application registration can grant significant control over the application's configuration, permissions, and behavior. If confirmed malicious, an attacker could modify the application's settings, permissions, and behavior, leading to unauthorized data access, privilege escalation, or the introduction of malicious behavior within the application's operations.

1`o365_management_activity` Workload=AzureActiveDirectory Operation="Add owner to application." 
2| eval app_id=mvindex('ModifiedProperties{}.NewValue', 0) 
3| eval app_displayName=mvindex('ModifiedProperties{}.NewValue', 1) 
4| stats max(_time) as lastTime values(ModifiedProperties{}.NewValue) by Operation, user, app_displayName, object 
5| `security_content_ctime(lastTime)` 
6| `o365_application_registration_owner_added_filter`

Data Source

Name Platform Sourcetype Source Supported App
O365 Add owner to application. N/A 'o365:management:activity' 'o365' N/A

Macros Used

Name Value
o365_management_activity sourcetype=o365:management:activity
o365_application_registration_owner_added_filter search *
o365_application_registration_owner_added_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
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
APT3
APT41
APT5
Dragonfly
FIN13
HAFNIUM
Kimsuky
Lazarus Group
Magic Hound

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

Application owners may be added for legitimate reasons, filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Application registration $app_displayName$ was assigned a new owner $object$ 30 60 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 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: 2