ID | Technique | Tactic |
---|---|---|
T1110 | Brute Force | Credential Access |
Detection: Crowdstrike Medium Severity Alert
Description
The following analytic detects a CrowdStrike alert with MEDIUM severity indicates a potential threat that requires prompt attention. This alert level suggests suspicious activity that may compromise security but is not immediately critical. It typically involves detectable but non-imminent risks, such as unusual behavior or attempted policy violations, which should be investigated further and mitigated quickly to prevent escalation of attacks.
Search
1`crowdstrike_stream`
2| rename event.EndpointIp as src_ip, event.EndpointName as src_host, event.UserName as user, event.IncidentDescription as description, event.IncidentType as type, event.NumbersOfAlerts as count_alerts, event.SeverityName as severity
3| stats count min(_time) as firstTime max(_time) as lastTime by src_ip, src_host, user, description, type, count_alerts, severity
4| where LIKE (severity, "%MEDIUM%")
5| `security_content_ctime(firstTime)`
6| `security_content_ctime(lastTime)`
7| `crowdstrike_medium_severity_alert_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
N/A | N/A | N/A | N/A | N/A |
Macros Used
Name | Value |
---|---|
crowdstrike_stream | sourcetype="CrowdStrike:Event:Streams:JSON" |
crowdstrike_medium_severity_alert_filter | search * |
crowdstrike_medium_severity_alert_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 Risk Event | True |
Implementation
To implement CrowdStrike stream JSON logs, use the Falcon Streaming API. Set up an API client, authenticate with your CrowdStrike credentials, and subscribe to the "CrowdStrike:Event:Streams:JSON" event stream. Process and store the JSON logs as needed, integrating them into your logging or SIEM system for monitoring and analysis.
Known False Positives
unknown
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A MEDIUM Severity Crowdstrike Alert found in $src_host$ | 49 | 70 | 70 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | CrowdStrike:Event:Streams |
CrowdStrike:Event:Streams:JSON |
Integration | ✅ Passing | Dataset | CrowdStrike:Event:Streams |
CrowdStrike:Event:Streams:JSON |
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: 1