Detection: Windows Export Certificate

Updated Date: 2024-05-16 ID: d8ddfa9b-b724-4df9-9dbe-f34cc0936714 Author: Michael Haag, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects the export of a certificate from the Windows Certificate Store. It leverages the Certificates Lifecycle log channel, specifically event ID 1007, to identify this activity. Monitoring certificate exports is crucial as certificates can be used for authentication to VPNs or private resources. If malicious actors export certificates, they could potentially gain unauthorized access to sensitive systems or data, leading to significant security breaches.

1`certificateservices_lifecycle` EventCode=1007 
2| xmlkv UserData_Xml 
3| stats count min(_time) as firstTime max(_time) as lastTime by Computer, SubjectName, UserData_Xml 
4| rename Computer as dest 
5| `security_content_ctime(firstTime)`
6| `security_content_ctime(lastTime)` 
7| `windows_export_certificate_filter`

Data Source

Name Platform Sourcetype Source Supported App
Windows Event Log CertificateServicesClient 1007 Windows icon Windows 'XmlWinEventLog' 'XmlWinEventLog:Microsoft-Windows-CertificateServicesClient-Lifecycle-System/Operational' N/A

Macros Used

Name Value
certificateservices_lifecycle (source=XmlWinEventLog:Microsoft-Windows-CertificateServicesClient-Lifecycle-System/Operational OR source=XmlWinEventLog:Microsoft-Windows-CertificateServicesClient-Lifecycle-User/Operational)
windows_export_certificate_filter search *
windows_export_certificate_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
T1552.004 Private Keys Credential Access
T1552 Unsecured Credentials Credential Access
T1649 Steal or Forge Authentication Certificates Credential Access
KillChainPhase.EXPLOITAITON
NistCategory.DE_AE
Cis18Value.CIS_10
Rocke
Scattered Spider
TeamTNT
APT29

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
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

To implement this analytic, you must collect Microsoft-Windows-CertificateServicesClient-Lifecycle-System/Operational or Microsoft-Windows-CertificateServicesClient-Lifecycle-User/Operational.

Known False Positives

False positives may be generated based on an automated process or service that exports certificates on the regular. Review is required before setting to alert. Monitor for abnormal processes performing an export.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
An certificate was exported on $dest$ from the Windows Certificate Store. 36 60 60
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 XmlWinEventLog:Microsoft-Windows-CertificateServicesClient-Lifecycle-System/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-CertificateServicesClient-Lifecycle-System/Operational XmlWinEventLog

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