Auditing Active Directory Permissions with Powershell

Active Directory permissions aren’t easy to audit.  It is a lot easier to delegate permissions to a user or a group than it is to figure out later who has what rights on what containers and organizational units.  I have taken a few runs at it, including a vbscript version which was terrible.  That is why I was very happy when I found this script by Microsoft Premier Field Engineer Ashley McGlone.  His script gives you the choice of a full dump of the local domain, or a list of the assigned (not inherited) permissions.

Because I work in a larger multi-domain forest, I wanted a script that would allow me to choose what domain to audit, and to also have more control over what data would be in the filtered list.  The resulting script is Get-OUPermissions.ps1.  In my script the filtered list looks for assigned rights containing Create, Write, Delete or All, as those are the ones I find interesting.  Using Where-Object was terribly slow, so I switched to a regex solution from a Scripting Guy article.  I have commented the script pretty heavily to show where I changed things from the original script.  My version wraps the original script in an advanced function, and so you can run it and use Get-Help to see all of the parameters and choices.  There is some pretty interesting things in here, but what stumped me for a while was how to use Get-ACL for an AD object outside the current domain.  What I came up was is something like this:
$a = Get-ADUser -Identity $env:username -server $dnsdom -Properties * $a.nTSecurityDescriptor |
Select-Object -ExpandProperty Access |
Select-Object *

By using the ntSecurityDescriptor you can specify the domain by using the DNS Domain Name in the Server parameter of the Get-AD* cmdlet.

Script Text

Get List of Computers from Active Directory

Get-ADComputerList.ps1 is pretty simple.  It gets a list of all the computers in the domain you specify.  Reported are the DNS Name, IP v4 Address, Active Directory Path and OS.  A comma delimited log file is written to your desktop.
Script Text

Compare Group Policy Objects

Our Active Directory lead recently complained to me that he didn’t have a good way to compare Group Policy Objects.  I had already written the Group Policy Reporter, which exports GPOs to HTML files, and it occurred to me that comparing two HTML files would be pretty easy.  But my experiments with Compare-Object led to some pretty ugly results.  I frequently compare documents using MS Word, and I decided to use Word to do the comparison of the files.

The new script, GPOCompare.ps1, makes a list of your GPOs and displays that list using Out-GridView.  After you select two GPOs, you are asked which is the “original” (earlier) GPO for Word to use as the original document.  The HTML reports are created, then a comparison is made using Word.  This script requires PowerShell 3, The Group Policy Management Console, and Word installed.

The Word COM object is not fun to work with in PowerShell.  In particular, you cannot use $Null for some of the unused parameters, and note that many must be explicit references, example [REF]$True.

Script Text

Upgrading from Server 2008 to Server 2012 R2 – Lessons Learned

I am a member of a terrific IT User group, Carolina IT Professional Group.  This group is focused on educating its members, and giving back to the community.  But what really keeps people to the end are the terrific door prizes.  At the July meeting, I won a copy of Server 2012 R2.  I had been running Server 2008 on my home network and decided that it was time to upgrade.  The first lesson is this:  Server 2008 is the Vista codebase, and Server 2012 R2 is the Windows 8.1 codebase.  You can’t upgrade from Vista to 8.1, nor can you upgrade to 2012 R2 from 2008.

A fresh OS install on my old domain controller — and fresh drives – was appropriate.  I downloaded an evaluation copy of Server 2012 R2 and installed it on one of my more capable workstations.  I installed the appropriate roles, moving AD and DNS over to it.  No problem. After migrating the home directories onto a 2TB drive,  I went on and installed a boot disk to replace the aging mirrored 500GB drives in the old DC.

I then installed my licensed copy of 2012 R2, and went looking for my home directories.   To make a long story short,  lesson two is remembering about the necessity of importing “foreign drives” when you move a disk between Windows installs.  Somehow along the way the security for the home drive folders got hosed, and I took a significant amount of time resetting the ACLs.

I have installed AD and DNS on my permanent DC, and am waiting for things to calm down before I remove those roles from the temporary DC.

The last lesson is this:  Server 2012 R2 has the same idiot UI as 8 and 8.1.  I was happy to find that Classic Shell works just fine at restoring a traditional start menu to Server 2012 R2.  For my thoughts on 8.1 and Classic Shell, visit this blog post.

Update: I have installed the “Windows Server Essentials Experience” which allows me to remotely backup all my workstations.  For more information, visit http://technet.microsoft.com/en-us/library/dn281793.aspx.

Remote Windows Update 3.1

Looking for a script to run Windows Update remotely?   WindowsUpdate.hta version 3.1 is an HTML application which allows you to connect to a remote machine, determine what patches it requires from Windows Update, and install the patches.  You can schedule a reboot time. This version allows you to look at he Windows Update log, and the log created by the program itself.  There is a button to allow you to change the update source to windowsupdate.com, which is helpful in places where WSUS or SUP is not working properly.  You can install all security patches, or select patches individually.

HTA files are best run from your local drive. Version 3.0 was released in 2011, version 3.1 only changes the background color to blue.  The transition color method I had used for the background is no longer supported in IE, and the program appeared to be broken.

Change _hta.txt extension to .HTA.
Script Text

Delete a List of Computer Accounts from Active Directory

Although I have spent most of my time recently writing PowerShell code, I still get requests from the field for vbscripts.  The security model differences make it more time consuming to explain how to run a PowerShell script than vbscript’s “double click this”.  DisablePCsFromList.vbs is an updated version of a 2006 vbscript which reads a text file with a list of computer accounts, and deletes the list.  A log file is written to the user desktop.