Detection: O365 SharePoint Malware Detection

Updated Date: 2024-11-14 ID: 583c5de3-7709-44cb-abfc-0e828d301b59 Author: Steven Dick Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies when a malicious file is detected within the SharePoint Online ecosystem. Attackers may stage and execute malicious files from within the Microsoft Office 365 ecosystem. Any detections from built-in Office 365 capabilities should be monitored and responded to appropriately. Certain premium Office 365 capabilities further enhance these detection and response functions.

Search

1`o365_management_activity` Operation=FileMalwareDetected 
2| stats values(Workload) as category, values(SourceFileName) as file_name values(ObjectId) as file_path, values(VirusInfo) as signature, count, min(_time) as firstTime, max(_time) as lastTime by Id, UserId 
3| rename Id as signature_id, UserId as user 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `o365_sharepoint_malware_detection_filter`

Data Source

No data sources specified for this detection.

Macros Used

Name	Value
o365_management_activity	`sourcetype=o365:management:activity`
o365_sharepoint_malware_detection_filter	`search *`

o365_sharepoint_malware_detection_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
T1204.002	Malicious File	Execution
T1204	User Execution	Execution

Installation

DE.CM

CIS 10

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

unknown

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

SharePoint detected a potentially malicious file $file_name$

Risk Object	Risk Object Type	Risk Score	Threat Objects
user	user	75	file_name

References

https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/anti-malware-protection-for-spo-odfb-teams-about?view=o365-worldwide

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