The following analytic identifies the PowerShell Cmdlet export-pfxcertificate utilizing Script Block Logging. This particular behavior is related to an adversary attempting to steal certificates local to the Windows endpoint within the Certificate Store.
- Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2023-02-01
- Author: Michael Haag, Splunk
- ID: ed06725f-6da6-439f-9dcc-ab30e891297c
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 `powershell` EventCode=4104 ScriptBlockText IN ("*export-pfxcertificate*") | rename Computer as dest | stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText dest user_id | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_powershell_export_pfxcertificate_filter`
The SPL above uses the following Macros:
windows_powershell_export_pfxcertificate_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/220.127.116.11/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
Known False Positives
It is possible administrators or scripts may run these commands, filtering may be required.
Associated Analytic Story
|36.0||60||60||A PowerShell Cmdlet related to exporting a PFX Certificate was ran on $dest$, attempting to export a certificate.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1