GitHub Repo

Detection: O365 SharePoint Malware Detection

Updated Date: 2026-05-13 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.

 1`o365_management_activity` Operation=FileMalwareDetected
 2  
 3| rename UserId as user, Id as signature_id
 4  
 5| 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
 6    BY signature_id, user, dest,
 7       src, vendor_account, vendor_product
 8  
 9| `security_content_ctime(firstTime)`
10  
11| `security_content_ctime(lastTime)`
12  
13| `o365_sharepoint_malware_detection_filter`

Data Source

Name Platform Sourcetype Source
Office 365 Universal Audit Log Other 'o365:management:activity' 'o365'

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
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 Finding (Notable) Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Intermediate Finding (Risk Event) No
TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events.

Known False Positives

No false positives have been identified at this time.

Associated Analytic Story

Finding

Title Entity Field Entity Type Risk Score
SharePoint detected a potentially malicious file $file_name$ user user 50

Threat Objects

Field Type
file_name file_name

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: 12