The following analytic is to identify the imports of Windows PowerShell Applocker commandlets. This technique was seen in Azorult malware where it drops an xml Applocker policy that will deny several AV product and then loaded using PowerShell Applocker commandlet.
- Type: TTP
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2022-06-30
- Author: Teoderick Contreras, Splunk
- ID: 102af98d-0ca3-4aa4-98d6-7ab2b98b955a
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 7 `powershell` EventCode=4104 ScriptBlockText="*Import-Module Applocker*" ScriptBlockText="*Set-AppLockerPolicy *" ScriptBlockText="* -XMLPolicy *" | stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID | rename Computer as dest | rename UserID as user | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_powershell_import_applocker_policy_filter`
The SPL above uses the following Macros:
windows_powershell_import_applocker_policy_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/188.8.131.52/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
Known False Positives
administrators may execute this command that may cause some false positive.
Associated Analytic Story
|49.0||70||70||A PowerShell script contains Import Applocker Policy command $ScriptBlockText$ with EventCode $EventCode$ on host $dest$|
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