ID | Technique | Tactic |
---|---|---|
T1649 | Steal or Forge Authentication Certificates | Credential Access |
Detection: Windows Steal Authentication Certificates CryptoAPI
Description
The following analytic detects the extraction of authentication certificates using Windows Event Log - CAPI2 (CryptoAPI 2). It leverages EventID 70, which is generated when a certificate's private key is acquired. This detection is significant because it can identify potential misuse of certificates, such as those extracted by tools like Mimikatz or Cobalt Strike. If confirmed malicious, this activity could allow attackers to impersonate users, escalate privileges, or access sensitive information, posing a severe risk to the organization's security.
Search
1`capi2_operational` EventCode=70
2| xmlkv UserData_Xml
3| stats count min(_time) as firstTime max(_time) as lastTime by Computer, UserData_Xml
4| rename Computer as dest
5| `security_content_ctime(firstTime)`
6| `security_content_ctime(lastTime)`
7| `windows_steal_authentication_certificates_cryptoapi_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Windows Event Log CAPI2 70 | Windows | 'xmlwineventlog' |
'XmlWinEventLog:Microsoft-Windows-CAPI2/Operational' |
N/A |
Macros Used
Name | Value |
---|---|
capi2_operational | (source=XmlWinEventLog:Microsoft-Windows-CAPI2/Operational) |
windows_steal_authentication_certificates_cryptoapi_filter | search * |
windows_steal_authentication_certificates_cryptoapi_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 this analytic, one will need to enable the Microsoft-Windows-CAPI2/Operational log within the Windows Event Log. Note this is a debug log for many purposes, and the analytic only focuses in on EventID 70. Review the following gist for additional enabling information.
Known False Positives
False positives may be present in some instances of legitimate applications requiring to export certificates. Filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Certificates were exported via the CryptoAPI 2 on $dest$. | 24 | 30 | 80 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-CAPI2/Operational |
XmlWinEventLog |
Integration | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-CAPI2/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: 2