Before we really start this post, I should mentioned that there’s no reason that the script discussed in this post can’t be run against an Organizational Unit (OU) that hasn’t been abandoned. It just worked out that I wrote the script in order to determine if an OU had be abandoned.

I threw a small script together in the last couple days and thought I’d share it. The reason for the script was because I may have had an Active Directory (AD) OU that was no longer being used. In order to determine if this was really the case, I wanted to check various properties on the user and computer objects in the OU, to include any nested OUs. These properties included the last logon time stamp, the last date the objects changed, and a few others.

The first couple of lines in the script set two different variables. The first one stores the Domain’s Distinguished Name, and the second one is assigned the location of the abandoned OU. The second variable is based partly on the first. This script requires the ActiveDirectory module and assumes it’s being run on PowerShell 3.0 or greater, as the AD module isn’t explicitly imported.

$DomainDN = ((Get-ADDomain).DistinguishedName)
$AbandonedOU = Get-ADObject -Filter * -SearchBase "OU=Finance,OU=Departments,$DomainDN"

In the next part of the script, we start to send the $AbandonedOU variable’s objects across the pipeline, to the Foreach-Object cmdlet. As each object passes across, we determine what type of AD object we’re dealing with. If it’s a user object, we set the $Command variable to the string, Get-ADUser. If it’s a computer object we set the $Command variable to the string, Get-ADComputer. If it’s neither, such as a nested OU, we’ll return to the $AbandonedOU variable and send the next object without assigning anything to the $Command variable (or running any of the upcoming code).

$AbandonedOU | ForEach-Object {
    If ($_.ObjectClass -eq 'user') {
        $Command = 'Get-ADUser'
    } ElseIf ($_.ObjectClass -eq 'computer') {
        $Command = 'Get-ADComputer'
    } Else {
        return
    }

Providing we have a user or computer AD object, we’ll run the code in the next example. This will execute the cmdlet, whether it be Get-ADUser or Get-ADComputer, returning the requested properties that we then calculate (think, customize).

    & $Command -Identity $_ -Properties * |
        Select-Object Name,
            @{N='Type';E={$_.ObjectClass}},
            @{N='Created';E={$_.whenCreated}},
            @{N='Last Logon TimeStamp';E={[datetime]::FromFileTime($_.LastLogonTimeStamp)}},
            @{N='Changed';E={$_.whenChanged}},
            @{N='Added To Domain By';E={$_.nTSecurityDescriptor.Owner}}
}

Finally, we sort the collection of objects we’ve returned and customized, and in my case, pump the data out to a CSV file at the root of my C:\ drive. As you’ll see below, I’ve included both the code in the previous example and the additional code.

    & $Command -Identity $_ -Properties * |
        Select-Object Name,
            @{N='Type';E={$_.ObjectClass}},
            @{N='Created';E={$_.whenCreated}},
            @{N='Last Logon TimeStamp';E={[datetime]::FromFileTime($_.LastLogonTimeStamp)}},
            @{N='Changed';E={$_.whenChanged}},
            @{N='Added To Domain By';E={$_.nTSecurityDescriptor.Owner}}
} | Sort-Object 'Last Logon TimeStamp' -Descending | Export-Csv -Path C:\AbandonedOU.csv -NoTypeInformation

I want to mention something about the line above that calculates the “Added To Domain By” property. In many environments this is going to only be <DOMAIN>\Domain Admins. The reason I added this, is because in the AD environment in which this ran, users, other than the Domain Admins, can join computers. I know this is a default; however, in many environments it is not allowed. This may or may not be a helpful property in your environment.

Cheers, and thanks for reading! I’ve included the complete script below.

$DomainDN = ((Get-ADDomain).DistinguishedName)
$AbandonedOU = Get-ADObject -Filter * -SearchBase "OU=Finance,OU=Departments,$DomainDN"

$AbandonedOU | ForEach-Object {
    If ($_.ObjectClass -eq 'user') {
        $Command = 'Get-ADUser'
    } ElseIf ($_.ObjectClass -eq 'computer') {
        $Command = 'Get-ADComputer'
    } Else {
        return
    }

    & $Command -Identity $_ -Properties * |
        Select-Object Name,
            @{N='Type';E={$_.ObjectClass}},
            @{N='Created';E={$_.whenCreated}},
            @{N='Last Logon TimeStamp';E={[datetime]::FromFileTime($_.LastLogonTimeStamp)}},
            @{N='Changed';E={$_.whenChanged}},
            @{N='Added To Domain By';E={$_.nTSecurityDescriptor.Owner}}
} | Sort-Object 'Last Logon TimeStamp' -Descending | Export-Csv -Path C:\AbandonedOU.csv -NoTypeInformation