ID | Technique | Tactic |
---|---|---|
T1114 | Email Collection | Collection |
T1114.002 | Remote Email Collection | Collection |
Detection: O365 Compliance Content Search Started
Description
The following analytic detects when a content search is initiated within the Office 365 Security and Compliance Center. It leverages the SearchCreated operation from the o365_management_activity logs under the SecurityComplianceCenter workload. This activity is significant as it may indicate an attempt to access sensitive organizational data, including emails and documents. If confirmed malicious, this could lead to unauthorized data access, potential data exfiltration, and compliance violations. Monitoring this behavior helps ensure the integrity and security of organizational data.
Search
1`o365_management_activity` Workload=SecurityComplianceCenter Operation=SearchCreated
2| rename user_id as user
3| stats count earliest(_time) as firstTime latest(_time) as lastTime by Operation, ObjectId, ExchangeLocations, user, Query
4|`security_content_ctime(firstTime)`
5|`security_content_ctime(lastTime)`
6| `o365_compliance_content_search_started_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
N/A | N/A | N/A | N/A | N/A |
Macros Used
Name | Value |
---|---|
o365_management_activity | sourcetype=o365:management:activity |
o365_compliance_content_search_started_filter | search * |
o365_compliance_content_search_started_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
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 |
Implementation
You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events.
Known False Positives
Compliance content searches may be executed for legitimate purposes, filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A new compliance content search was started by $user$ | 42 | 60 | 70 |
References
-
https://learn.microsoft.com/en-us/purview/ediscovery-content-search-overview
-
https://learn.microsoft.com/en-us/purview/ediscovery-keyword-queries-and-search-conditions
-
https://learn.microsoft.com/en-us/purview/ediscovery-search-for-activities-in-the-audit-log
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