Command Discovery Unleashed (Part 1)

by Apr 16, 2019

Whenever you enter a command in PowerShell, a series of events takes place to figure out where the command is located. This starts with a PreCommandLookupAction which you can use to log commands. Have a look at this:

$ExecutionContext.InvokeCommand.PreCommandLookupAction = {

$whitelist = @(

    if ($Command -notin $whitelist -and $Obj.CommandOrigin -eq 'Runspace')

When you run this, every command you enter will be echoed to the console – except for the commands listed in $whitelist. This illustrates how the PreCommandLookupAction works: it fires whenever you enter a command, and you could write the commands to a log file as well. – PowerShell Conference EU 2019 – June 4-7, Hannover Germany – visit There aren’t too many trainings around for experienced PowerShell scripters where you really still learn something new. But there’s one place you don’t want to miss: PowerShell Conference EU – with 40 renown international speakers including PowerShell team members and MVPs, plus 350 professional and creative PowerShell scripters. Registration is open at, and the full 3-track 4-days agenda becomes available soon. Once a year it’s just a smart move to come together, update know-how, learn about security and mitigations, and bring home fresh ideas and authoritative guidance. We’d sure love to see and hear from you!

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