Building and Populating Active Directory for my Homelab

There are a multitude of Active Directory how-to blog posts and videos out there. This is my experience putting together a quick and dirty Active Directory server, populating it with OUs and users, and getting users randomly logged in each day. I’m going to skip the standard steps for installing AD as it’s well documented in other blogs, and it’s the populating of AD that’s more interesting to me.

Why put in all this work you ask? I’m doing some experimentation in AD, and rather than blow up a production environment, I want a working and populated AD at home. I also need users to “log in” randomly so I can use the login activity to write some scripts. So, here’s how I did it.

Step 1 was to actually install Active Directory. Again, there are numerous blogs about how to do this. Since I was running Server 2016 in evaluation mode, I wasn’t going to do a lot of customizing since it was just going to expire eventually anyway. I had already configured 2016 for DNS and DHCP for my lab network, so installing AD was as easy as adding the role and management utilities from the Server Manager. Utilizing the “Next” button repeatedly, I created a new forest and domain for the lab.

The next step was to populate the directory. For this, I went with the “CreateDemoUsers” script from the Microsoft TechNet Gallery. I downloaded the PowerShell script and accompanying CSV and executed the script. In minutes, I had a complete company including multiple OUs filled with over a thousand user accounts and groups. Each user had a complete profile, including title, location and manager.

With my sample Active Directory populated, my next goal was to record random logins for these users. I needed this initially for some scripts I was writing, but my eventual goal was to generate regular activity to bring into Splunk. For my simulated login activity, I wrote a script to pick a user at random and execute a dummy command as that user so that a login was recorded on their user record. I began by modifying the “Default Domain Controller policy” in Group Policy Management. I added “Domain Users” to “Allow log on locally.” (This is found in Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> User Rights Assignment.) This step isn’t necessary if the script is running from a domain member, but since I didn’t have any computers added to the domain, this would allow me to run the script directly on the domain controller.

Here is the script that I created. I put it in c:\temp so it could be run by any user account.

# Login.ps1

$aduser = Get-ADUser -Filter * | Select-Object -Property UserPrincipalName | Sort-Object{Get-Random} | Select -First 1
$username = $aduser.UserPrincipalName
$password = ConvertTo-SecureString 'Password1' -AsPlainText -Force

$credential = New-Object System.Management.Automation.PSCredential $username, $password
Start-Process hostname.exe -Credential $credential

I wanted my user base as a whole to log in on average every 90 days, which meant that I wanted about 11 users per day to log in. Easy enough, I created a scheduled task to run at 12:00am every day and repeat every 2 hours. That was close enough for my purposes.

Since I was running this on a lone DC in a lab, I ran it as NT AUTHORITY\SYSTEM so I didn’t have to mess with passwords. The task runs powershell.exe with the arguments -ExecutionPolicy Bypass c:\temp\login.ps1.

After saving the task, I right-clicked and clicked “Run.” Because I chose hostname.exe as the execution target, the program opened and immediately closed. While this briefly flashed on my screen when testing, nothing appears on the screen when running this as a scheduled task. A quick look through the event log confirmed that user “LEClinton” logged in, and a look at Lisa Clinton’s AD record shows that she did indeed log in.

While my eventual goal is to script all of the installation and configuration, this was enough to get the other work I needed to do done, as well as provide a semi-active AD environment for further testing and development.

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