Detection: Crowdstrike Medium Identity Risk Severity

Updated Date: 2024-07-15 ID: c23b425c-9024-4bd7-b526-c18a4a51d93e Author: Teoderick Contreras, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects CrowdStrike alerts for Medium Identity Risk Severity with a risk score of 55 or higher. These alerts indicate significant vulnerabilities in user identities, such as suspicious behavior or compromised credentials. Promptly investigating and addressing these alerts is crucial to prevent potential security breaches and ensure the integrity and protection of sensitive information and systems.

1`crowdstrike_identities` riskScoreSeverity = "MEDIUM" OR riskScore >= 0.55 AND riskScore < 0.70 
2| rename riskFactors{}.severity as severity, riskFactors{}.type as risk_type, roles{}.type as role_type, accounts{}.domain as domain, accounts{}.dn as dn, accounts{}.samAccountName as user 
3| stats count min(_time) as firstTime max(_time) as lastTime by  domain dn primaryDisplayName risk_type severity riskScore riskScoreSeverity user role_type 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `crowdstrike_medium_identity_risk_severity_filter`

Data Source

Name Platform Sourcetype Source Supported App
N/A N/A N/A N/A N/A

Macros Used

Name Value
crowdstrike_identities sourcetype=crowdstrike:identities
crowdstrike_medium_identity_risk_severity_filter search *
crowdstrike_medium_identity_risk_severity_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
T1110 Brute Force Credential Access
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
APT28
APT38
APT39
DarkVishnya
Dragonfly
FIN5
Fox Kitten
HEXANE
OilRig
Turla

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

To implement crowdstrike:identities logs, use the Falcon Streaming API. Set up an API client, authenticate with your CrowdStrike credentials, and subscribe to the "crowdstrike:identities" event stream. Process and store the 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
Medium Identity Risk Score Severity found on $domain$ 70 100 70
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 crowdstrike:identities crowdstrike:identities
Integration ✅ Passing Dataset crowdstrike:identities crowdstrike:identities

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