Detection: O365 Service Principal New Client Credentials

Updated Date: 2024-05-12 ID: a1b229e9-d962-4222-8c62-905a8a010453 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the addition of new credentials for Service Principals within an Office 365 tenant. It uses O365 audit logs, focusing on events related to credential modifications or additions in the AzureActiveDirectory workload. This activity is significant because Service Principals represent application identities, and their credentials allow applications to authenticate and access resources. If an attacker successfully adds or modifies these credentials, they can impersonate the application, leading to unauthorized data access, data exfiltration, or malicious operations under the application's identity.

Search

1 `o365_management_activity` Workload=AzureActiveDirectory Operation="Update application*Certificates and secrets management " 
2|  stats earliest(_time) as firstTime latest(_time) as lastTime by user ModifiedProperties{}.NewValue object ObjectId 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `o365_service_principal_new_client_credentials_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
O365	N/A	`'o365:management:activity'`	`'o365'`	N/A

Macros Used

Name	Value
o365_management_activity	`sourcetype=o365:management:activity`
o365_service_principal_new_client_credentials_filter	`search *`

o365_service_principal_new_client_credentials_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
T1098.001	Additional Cloud Credentials	Privilege Escalation

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

Service Principal client credential modifications may be part of legitimate administrative operations. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
New credentials added for Service Principal $object$	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	`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