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Creative Commons Attribution 4.0 International License
© Rakhesh Sasidharan

Find the computer from where an AD account is locked out

I want to find out where from a user account is locked out in my domain.

The manual way to do this would be to open up Event Viewer, scan the event logs on the DC for event ID 4740, open it up and see the message to identify the machine from where this account was locked out. But using PowerShell we can obviously automate this way easily!

First things first: how to scan the event logs using PowerShell? You can use either of Get-EventLog or Get-WinEvent. The former only works on the classic event logs while the latter works on both the classic and newer event logs such as those found in Windows Vista and later. I find the latter faster too, so let’s use that. Here’s me running that cmdlet to filter the security logs for event ID 4740 on a remote DC:

There’s only one event here so the details of that are returned. It gives us all the info we need at a glance: user name “User01” is locked thanks to a bad password attempt from the computer “MANGO”.

Neat!

Now let’s go about making this prettier and better.

In the code above I am specifying the domain controller to query. That’s only helpful if I have an idea of the machine or site the user is trying to login to, and so know the domain controller responsible for that site. A better approach would be to query the domain controller with the PDC Emulator FSMO role for event ID 4740. This DC is the one that eventually processes the account lockout requests for all accounts in the domain.

The cmdlet Get-ADDomainContoller gives you the domain controller of the site you are in. Adding the switch -Filter * gives you all the domain controllers in the domain. And piping this through a where-object to filter out the domain controller with the “PDC Emulator” FSMO role gives you the domain controller we are interested in. Like thus:

The snippet above returns an object for the DC with the PDC Emulator role, to extract just the name do thus:

Next, let’s go about presenting the output above in a tidier format.

One thing to note is that all the info we want is in a property called Message.

So one option would be to do some fancy filtering using foreach-object like thus:

This will list out the multiple lockout entries with the timestamp on top in red.

A better option, however, is to use the Properties property, which is an array containing exactly the info we want as values.

Format-Table is your friend here:

A one line code that’s way better than opening Event Viewer and filtering through the logs manually.

And if you want to filter by the locked out status of a specific $user, pipe the output through a where-object like thus:

Find the computer from where an AD account is locked out by rakhesh is licensed under a Creative Commons Attribution 4.0 International License.