a gist copy of patch extract by Greg Lanaris

PatchExtract.ps1

<#

 ____     ______   ______  ____     __  __     
/\  _`\  /\  _  \ /\__  _\/\  _`\  /\ \/\ \    
\ \ \L\ \\ \ \L\ \\/_/\ \/\ \ \/\_\\ \ \_\ \   
 \ \ ,__/ \ \  __ \  \ \ \ \ \ \/_/_\ \  _  \  
  \ \ \/   \ \ \/\ \  \ \ \ \ \ \L\ \\ \ \ \ \ 
   \ \_\    \ \_\ \_\  \ \_\ \ \____/ \ \_\ \_\
    \/_/     \/_/\/_/   \/_/  \/___/   \/_/\/_/
                                               
                                               
 ____     __   __   ______  ____     ______   ____     ______   
/\  _`\  /\ \ /\ \ /\__  _\/\  _`\  /\  _  \ /\  _`\  /\__  _\  
\ \ \L\_\\ `\`\/'/'\/_/\ \/\ \ \L\ \\ \ \L\ \\ \ \/\_\\/_/\ \/  
 \ \  _\L `\/ > <     \ \ \ \ \ ,  / \ \  __ \\ \ \/_/_  \ \ \  
  \ \ \L\ \  \/'/\`\   \ \ \ \ \ \\ \ \ \ \/\ \\ \ \L\ \  \ \ \ 
   \ \____/  /\_\\ \_\  \ \_\ \ \_\ \_\\ \_\ \_\\ \____/   \ \_\
    \/___/   \/_/ \/_/   \/_/  \/_/\/ / \/_/\/_/ \/___/     \/_/
                                                                
                                                                
 __  __      _          __     
/\ \/\ \   /' \       /'__`\  
\ \ \ \ \ /\_, \     /\_\L\ \  
 \ \ \ \ \\/_/\ \    \/_/_\_<_ 
  \ \ \_/ \  \ \ \  __ /\ \L\ \
   \ `\___/   \ \_\/\_\\ \____/
    `\/__/     \/_/\/_/ \/___/ 


================
PATCHEXTRACT.PS1
=================
Version 1.3 Microsoft MSU Patch Extraction and Patch Organization Utility by Greg Linares (@Laughing_Mantis)

This Powershell script will extract a Microsoft MSU update file and then organize the output of extracted files and folders.

Organization of the output files is based on the patch's files and will organize them based on their archicture (x86, x64, or wow64)
as well as their content-type, ie: resource and catalog files will be moved to a JUNK subfolder and patch binaries and index files will 
goto a PATCH folder.

This script was developed in order to aid reverse engineers in quickly organizing patches so they can be binary diffed faster and easier. 
This was especially developed with the new bulk Microsoft Kernel patches in mind.

Example output folder structure ouput would be similar to this:

C:\PATCHES\MS15-XXX\PRE
    -x86
        - x86 Binary patched files
    -x64
        - x64 binary patched files
    -WOW64 
        - syswow64 binary patched files
    -JUNK
        - resource, catalog, mum, and other non-binary based patched files
    -PATCH
        - original patch, cabs and xml files from the extraction
    -MSIL 
        - MSIL .NET binary patched files ***New in Version 1.1***
    -NOSSU
        - Exclude the SSU CAB in the extraction process

    Directories will automagically be organized into filename-version to remove garbage filler folder names
        
        
=============
REQUIREMENTS
=============
'expand.exe' to be present in %WINDIR%\SYSTEM32 (it is by default) - It will execute this file @ the current users permissions
A valid Microsoft MSU patch file to extract (PATCH variable)
Directory and File write/creation permissions to the PATH folder specified
        
    
=======    
USAGE
=======

Powershell -ExecutionPolicy Bypass -File PatchExtract.ps1 -Patch C:\Patches\Windows6.1-KB3088195-x64.msu -Path C:\Patches\MS15-XXX\POST\ 


This would extract the patch file C:\Patches\Windows6.1-KB3088195-x64.msu to the folder C:\Patches\MS15-XXX\POST\.
It will then create all the sub organization folders within C:\Patches\MS15-XXX\POST\ folder.

(Note: the optional Powershell parameters '-ExecutionPolicy Bypass' is necessary in some environments to overcome Powershell execution restrictions)

==========
ARGUMENTS
==========
-PATCH <STRING:Filename> [REQUIRED] [NO DEFAULT]
    Specifies the MSU file that will be extracted to the specified PATH folder and then organized into the x86, x64, WOW, JUNK, and BIN folders specified
    Extract command will be "expand -F:* <PATCH> <PATH>"
    Non MSU files have not been tested however if the extraction does not generate a CAB file of the same name (indicator of successful extraction of MSU files)
    the script assumes extraction failed.
    
-PATH <STRING:FolderPath> [REQUIRED] [NO DEFAULT]
    Specified the folder that the PATCH file will be extracted and organized into
    If the specified folders does not exist yet, the user will be prompted if they want to create it.
    Relative paths '.\POST' can be used but it has not extensively been tested.

    ***New in Version 1.1***
    The -PATH variable may be now omitted to expand to current directory
    

-x86 <STRING:Foldername> [OPTIONAL] [DEFAULT='x86']

    Specifies the folder name within $PATH to store x86 patch binaries
    example: -x86 32bit
    
    
-x64 <STRING:Foldername> [OPTIONAL] [DEFAULT='x64']

    Specifies the folder name within $PATH to store x64 patch binaries
    example: -x64 64bit
    
-WOW <STRING:Foldername> [OPTIONAL] [DEFAULT='WOW64']

    Specifies the folder name within $PATH to store wow64 type patch binaries
    example: -WOW sysWOW64

-MSIL <STRING:Foldername> [OPTIONAL] [DEFAULT='MSIL']

    *** New in Version 1.1***
    Specifies the folder name within $PATH to store .NET type patch binaries
    example: -MSIL DOTNET
    
-JUNK <STRING:Foldername> [OPTIONAL] [DEFAULT='JUNK']

    Specifies the folder name within $PATH to store resource, catalog, and other generally useless for diffing patch binaries
    example: -JUNK res
    
    
-BIN <STRING:Foldername> [OPTIONAL] [DEFAULT='PATCH']

    Specifies the folder name within $PATH to store extraction xml and original patch msu and cab files
    example: -BIN bin

- NOSSU <SWITCH> [OPTIONAL] [DEFAULT=$false]
    Excludes the servicing stack CAB from extraction (if present)

================
VERSION HISTORY
================
I originally wrote this as an ugly batch file sometime between 2014 and 2015 as a way to organize folders but it was incomplete and buggy

Oct 15, 2015 - Initial Public Release 1.0
Oct 20, 2016 - Version 1.1 Released
                * Bug fixes handling new naming format for patch .cab files
                * Added the ability to auto-extract to the same directory as current PATCH 
                * filtered output directory name format to aid in bindiffing

Oct 20, 2016 - Version 1.2 Released
                * Bug fixes handling MSIL renaming issues and collisions in renameing patch folders

Nov 7, 2016 - Version 1.25 Released
                * Added hack to handle subsequent CAB files Microsoft Added in Windows 10 Cumulative Patches - will make a better way to handle this in 1.3 

March 15, 2017 - Version 1.3 Released
                * Color Change to sweet vaporwave retro 80s colors
                * Cleaned up some awful code that I must have been on some amazing substances when I wrote
                * Spent several hours making a rad ASCII Logo
                * Most importantly fixed the Sub-cab auto-extraction method that Microsoft introduced late 2016
August 23, 2020 - Version 1.31 - Unofficial update by wumb0
                * Fixed extracting command (Start-Process -> iex). There's a bug in powershell that breaks Start-Process with arg lists that have literal quotes
                * Supressed output of expand.exe commands to cut down on script runtimes
March 24, 2021 - Version 1.32 - Unofficial update by wumb0
                * Update script to handle this month's update to the patch packaging format
                * Simplify recursive CAB extraction into a loop
                * Add option to skip the SSU CAB
                * Silenced a lot of output


==========
LICENSING
==========
This script is provided free as beer.  It probably has some bugs and coding issues, however if you like it or find it useful please give me a shout out on twitter @Laughing_Mantis.  
Feedback is encouraged and I will be likely releasing new scripts and tools and training in the future if it is welcome.


-GLin

#>




Param
(

    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [ValidateNotNullOrEmpty()]
    [string]$PATCH = "",
    
    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [string]$PATH = "",
    
    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [string]$x86 = "x86",
    
    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [string]$x64 = "x64",
    
    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [string]$WOW = "WOW64",

    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [string]$MSIL = "MSIL",
    
    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [string]$JUNK = "JUNK",
    
    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [string]$BIN = "PATCH",

    [Parameter(ValueFromPipelineByPropertyName = $true)]
    [switch]$NOSSU = $false
        
)

Clear-Host
$ASCIIART = @"
 ____     ______   ______  ____     __  __     
/\  _`\  /\  _  \ /\__  _\/\  _`\  /\ \/\ \   
\ \ \L\ \\ \ \L\ \\/_/\ \/\ \ \/\_\\ \ \_\ \   
 \ \ ,__/ \ \  __ \  \ \ \ \ \ \/_/_\ \  _  \  
  \ \ \/   \ \ \/\ \  \ \ \ \ \ \L\ \\ \ \ \ \ 
   \ \_\    \ \_\ \_\  \ \_\ \ \____/ \ \_\ \_\
    \/_/     \/_/\/_/   \/_/  \/___/   \/_/\/_/
                                               
                                               
 ____     __   __   ______  ____     ______   ____     ______   
/\  _`\  /\ \ /\ \ /\__  _\/\  _`\  /\  _  \ /\  _`\  /\__  _\  
\ \ \L\_\\ `\`\/'/'\/_/\ \/\ \ \L\ \\ \ \L\ \\ \ \/\_\\/_/\ \/  
 \ \  _\L `\/ > <     \ \ \ \ \ ,  / \ \  __ \\ \ \/_/_  \ \ \  
  \ \ \L\ \  \/'/\`\   \ \ \ \ \ \\ \ \ \ \/\ \\ \ \L\ \  \ \ \ 
   \ \____/  /\_\\ \_\  \ \_\ \ \_\ \_\\ \_\ \_\\ \____/   \ \_\
    \/___/   \/_/ \/_/   \/_/  \/_/\/ / \/_/\/_/ \/___/     \/_/
                                                                
                                                                
 __  __      _          __     
/\ \/\ \   /' \       /'__`\   
\ \ \ \ \ /\_, \     /\_\L\ \  
 \ \ \ \ \\/_/\ \    \/_/_\_<_ 
  \ \ \_/ \  \ \ \  __ /\ \L\ \
   \ `\___/   \ \_\/\_\\ \____/
    `\/__/     \/_/\/_/ \/___/ 
"@

Write-Host $ASCIIART -ForegroundColor Magenta
Start-Sleep -s 3


if ($PATCH -eq "")
{
    Throw ("Error: No PATCH file specified.  Specify a valid Microsoft MSU Patch with the -PATCH argument")
   
}

if ((Split-Path $PATCH -Parent) -eq "")
{
    # First look in current working directory for the relative filename
    $CurrentDir = $(get-location).Path;
    $PATCH = $CurrentDir + "\" + $PATCH

    # if that doesnt work we look in the current script directory (less likely)
    # but hey we tried
    if (!(Test-Path $PATCH))
    {
        $scriptDir = Split-Path -Path $MyInvocation.MyCommand.Definition -Parent
        $PATCH = $scriptDir + "\" + $PATCH
    }
}

if (!(Test-Path $PATCH))
{
    Throw ("Error: Specified PATCH file ($PATCH) does not exist.  Specify a valid Microsoft MSU Patch file with the -PATCH argument.")
}

if ($PATH -eq "")
{
    $PATH = Split-Path $PATCH -Parent
    write-Host ("PATH = $PATH") -ForegroundColor White
    Write-Host ("No PATH folder specified.  Will extract to $PATH folder.") -ForegroundColor White
    
}

#Bug Fix (Resolve-Path Error if invalid path was specified before the path was created)




if (!($PATCH.ToUpper().EndsWith(".MSU")))
{
    Do 
    {
        $Attempt = Read-Host ("Warning: Specified PATCH file ($PATCH) is not a MSU file type. Do you still want to attempt extraction? [Y] or [N]")
    }
    Until ('Y', 'y', 'n', 'N' -ccontains $Attempt)
    if ($Attempt.ToUpper() -eq 'N')
    {
        Write-Host ("Exiting...") -ForegroundColor DarkMagenta
        Exit
    }
}

if (!(Test-Path $PATH))
{
    Do 
    {
        $Attempt = Read-Host ("Warning: Specified PATH folder ($PATH) does not exist. Do you want to create it? [Y] or [N]")
    }
    Until ('Y', 'y', 'n', 'N' -ccontains $Attempt)
    if ($Attempt.ToUpper() -eq 'N')
    {
        Write-Host ("Exiting...") -ForegroundColor DarkMagenta
        Exit
    }
    else
    {
        New-Item $PATH -Force -ItemType Directory
        Write-Host "Created $PATH Folder" -ForegroundColor Cyan
    }
}

$PATCH = Resolve-Path $PATCH
$PATH = Resolve-Path $PATH

Write-Host "Patch to Extract: $PATCH" -ForegroundColor Magenta
Write-Host "Extraction Path: $PATH" -ForegroundColor Magenta
Write-Host "x86 File Storage Folder Name: $x86" -ForegroundColor Magenta
Write-Host "x64 File Storage Folder Name: $x64" -ForegroundColor Magenta
Write-Host "WOW64 File Storage Folder Name: $WOW" -ForegroundColor Magenta
Write-Host "MSIL File Storage Folder Name: $MSIL" -ForegroundColor Magenta
Write-Host "Junk File Storage Folder Name: $JUNK" -ForegroundColor Magenta
Write-Host "Orignal Patch File Storage Folder Name: $BIN" -ForegroundColor Magenta



$PATCHx86 = Join-Path -path $PATH -ChildPath $x86
$PATCHx64 = Join-Path -path $PATH -ChildPath $x64
$PATCHWOW = Join-Path -path $PATH -ChildPath $WOW
$PATCHMSIL = Join-Path -path $PATH -ChildPath $MSIL
$PATCHJUNK = Join-Path -path $PATH -ChildPath $JUNK
$PATCHCAB = Join-Path -path $PATH -ChildPath $BIN


if (!(Test-Path $PATCHx86 -pathType Container))
{
    New-Item $PATCHx86 -Force -ItemType Directory
    Write-Host "Making $PATCHx86 Folder" -ForegroundColor Cyan
}

if (!(Test-Path $PATCHx64 -pathType Container))
{
    New-Item $PATCHx64 -Force -ItemType Directory
    Write-Host "Making $PATCHx64 Folder" -ForegroundColor Cyan
}

if (!(Test-Path $PATCHWOW -pathType Container))
{
    New-Item $PATCHWOW -Force -ItemType Directory
    Write-Host "Making $PATCHWOW Folder" -ForegroundColor Cyan
}

if (!(Test-Path $PATCHMSIL -pathType Container))
{
    New-Item $PATCHMSIL -Force -ItemType Directory
    Write-Host "Making $PATCHMSIL Folder" -ForegroundColor Cyan
}

if (!(Test-Path $PATCHJUNK -pathType Container))
{
    New-Item $PATCHJUNK -Force -ItemType Directory
    Write-Host "Making $PATCHJUNK Folder" -ForegroundColor Cyan
}

if (!(Test-Path $PATCHCAB -pathType Container))
{
    New-Item $PATCHCAB -Force -ItemType Directory
    Write-Host "Making $PATCHCAB Folder" -ForegroundColor Cyan
}


$SYSPATH = Join-Path -path (get-item env:\windir).Value -ChildPath "system32"

$EXPAND = Join-Path -path $SYSPATH -ChildPath "expand.exe"


if (!(Test-Path $EXPAND))
{
    Throw ("Error: Cannot find 'Expand.exe' in the $SYSPATH folder.")
} 

$ARG = '-F:* ' + '"' + $PATCH + '" ' + '"' + $PATH + '"'

Write-Host "Executing the following command: $EXPAND $ARG" -ForegroundColor Cyan

# https://github.com/PowerShell/PowerShell/issues/5576
iex("$EXPAND $ARG | Out-Null") | Out-Null

$CABS = Get-Childitem -Path $PATH -Filter *.cab

while ($null -ne $CABS) {
    foreach ($CAB in $CABS)
    {
        Write-Host "CAB File: $CAB" -ForegroundColor White
        if (!($CAB.Name -eq "WSUSSCAN.cab" -or ($NOSSU -and $CAB.Name -like "SSU-*")))
        {
            $CAB = Join-Path -path $PATH -ChildPath $CAB
            Write-Host "Main-Cab: $CAB" -ForegroundColor Magenta
            if (Test-Path $CAB)
            {
                # add unique characters to the filename to prevent name collisions
                $hash = Get-FileHash -Algorithm MD5 $CAB
                $NEWCAB = $CAB.SubString(0, $CAB.LastIndexOf(".")) + "-" + $HASH.Hash.SubString(0, 5) + ".cab"
                Move-Item $CAB $NEWCAB -Force -ErrorAction SilentlyContinue
                $CAB = $NEWCAB
                $ARG = '-F:* ' + '"' + $CAB + '" ' + '"' + $PATH + '"'
                Write-Host "Executing the following command: $EXPAND $ARG" -ForegroundColor Cyan
                iex("$EXPAND $ARG | Out-Null") | Out-Null
                Write-Host "Moving $CAB to $PATCHCAB" -ForegroundColor Magenta
                Move-Item $CAB $PATCHCAB -Force -ErrorAction SilentlyContinue
            }
            else
            {
                Throw "Error: Patch .CAB File [$CAB] could not be located.  Patch Extraction failed - please send notification of this error to @Laughing_Mantis."
            }
        }
        else
        {
            Write-Host "Moving $CAB to $PATCHCAB" -ForegroundColor Magenta
            Move-Item $CAB $PATCHCAB -Force -ErrorAction SilentlyContinue
        }
    }
    $CABS = Get-Childitem -Path $NEW -Filter *.cab
}

$PATCHFolders = Get-ChildItem -Path $PATH -Force -ErrorAction SilentlyContinue | where {$_.Attributes -eq 'Directory'}

Write-Host "Sorting patch files into the correct folders"
foreach ($folder in $PATCHFolders)
{
    if ($folder.Name.Contains(".resources_"))
    {
        Move-Item $folder.FullName $PATCHJUNK -Force
        #Write-Host "Moving $folder to $PATCHJUNK" -ForegroundColor Cyan
        Continue
    }
    else
    {
        if ($folder.Name.StartsWith("x86_"))
        {
            Move-Item $folder.FullName $PATCHx86 -Force
            #Write-Host "Moving $folder to $PATCHx86" -ForegroundColor Cyan
            Continue
        }
        
        if ($folder.Name.StartsWith("amd64_"))
        {
            Move-Item $folder.FullName $PATCHx64 -Force
            #Write-Host "Moving $folder to $PATCHx64" -ForegroundColor Cyan
            Continue
        }
        
        if ($folder.Name.StartsWith("wow64_"))
        {
            Move-Item $folder.FullName $PATCHWOW -Force
            #Write-Host "Moving $folder to $PATCHWOW" -ForegroundColor Cyan
            Continue
        }

        if ($folder.Name.StartsWith("msil_"))
        {
            Move-Item $folder.FullName $PATCHMSIL -Force
            #Write-Host "Moving $folder to $PATCHMSIL" -ForegroundColor Cyan
            Continue
        }
    }
}

<# PRETTY BINDIFF OUTPUT - changes folder names from x86-microsoft-windows-filename-hash-version-garbage to filename-version #>

$PATCHFolders = Get-ChildItem -Path $PATCHx86 -Force -ErrorAction SilentlyContinue | where {$_.Attributes -eq 'Directory'}

foreach ($folder in $PATCHFolders)
{
    if ($folder -like "x86_microsoft-windows-*")
    {
        $newfolder = $folder.Name.Replace("x86_microsoft-windows-", "")
        $newname = $newfolder.Split("_")[0]
        $version = $newfolder.Split("_")[2]
        $newname = $newname + "_" + $version
        #Write-Host ("Renaming $folder to $newname") -ForegroundColor Magenta
        Rename-Item -path $folder.FullName -newName ($newname)
    }
    elseif ($folder -like "x86_*")
    {
        $newfolder = $folder.Name.Replace("x86_", "")
        $newname = $newfolder.Split("_")[0]
        $version = $newfolder.Split("_")[2]
        $newname = $newname + "_" + $version
        #Write-Host ("Renaming $folder to $newname") -ForegroundColor Cyan
        Rename-Item -path $folder.FullName -newName ($newname)
    }
}

$PATCHFolders = Get-ChildItem -Path $PATCHx64 -Force -ErrorAction SilentlyContinue | where {$_.Attributes -eq 'Directory'}

foreach ($folder in $PATCHFolders)
{
    if ($folder -like "amd64_microsoft-windows-*")
    {
        $newfolder = $folder.Name.Replace("amd64_microsoft-windows-", "")
        $newname = $newfolder.Split("_")[0]
        $version = $newfolder.Split("_")[2]
        $newname = $newname + "_" + $version
        #Write-Host ("Renaming $folder to $newname") -ForegroundColor Magenta
        Rename-Item -path $folder.FullName -newName ($newname)
    }
    elseif ($folder -like "amd64_*")
    {
        $newfolder = $folder.Name.Replace("amd64_", "")
        $newname = $newfolder.Split("_")[0]
        $version = $newfolder.Split("_")[2]
        $newname = $newname + "_" + $version
        #Write-Host ("Renaming $folder to $newname") -ForegroundColor Cyan
        Rename-Item -path $folder.FullName -newName ($newname)
    }
}

$PATCHFolders = Get-ChildItem -Path $PATCHWOW -Force -ErrorAction SilentlyContinue | where {$_.Attributes -eq 'Directory'}

foreach ($folder in $PATCHFolders)
{
    if ($folder -like "wow64_microsoft-windows-*")
    {
        $newfolder = $folder.Name.Replace("wow64_microsoft-windows-", "")
        $newname = $newfolder.Split("_")[0]
        $version = $newfolder.Split("_")[2]
        $newname = $newname + "_" + $version
        #Write-Host ("Renaming $folder to $newname") -ForegroundColor Magenta
        Rename-Item -path $folder.FullName -newName ($newname)
    }
    elseif ($folder -like "wow64_*")
    {
        $newfolder = $folder.Name.Replace("wow64_", "")
        $newname = $newfolder.Split("_")[0]
        $version = $newfolder.Split("_")[2]
        $newname = $newname + "_" + $version
        #Write-Host ("Renaming $folder to $newname") -ForegroundColor Cyan
        Rename-Item -path $folder.FullName -newName ($newname)
    }
}

$PATCHFolders = Get-ChildItem -Path $PATCHMSIL -Force -ErrorAction SilentlyContinue | where {$_.Attributes -eq 'Directory'}

foreach ($folder in $PATCHFolders)
{
    if ($folder -like "msil_*")
    {
        $newfolder = $folder.Name.Replace("msil_", "")
        $newname = $newfolder.Split("_")[0]
        $version = $newfolder.Split("_")[2]
        $newname = $newname + "_" + $version
        #Write-Host ("Renaming $folder to $newname") -ForegroundColor Cyan
        Rename-Item -path $folder.FullName -newName ($newname)
    }

}

$Junkfiles = Get-ChildItem -Path $PATH -Force -ErrorAction SilentlyContinue


foreach ($JunkFile in $Junkfiles)
{
    
    try
    {
        if (($JunkFile.Name.EndsWith(".manifest")) -or ($JunkFile.Name.EndsWith(".cat")) -or ($JunkFile.Name.EndsWith(".mum")))
        {
            Move-Item $JunkFile.FullName $PATCHJUNK -Force -ErrorAction SilentlyContinue
            #Write-Host "Moving $JunkFile to $PATCHJUNK" -ForegroundColor Magenta
            Continue
        }
        
        if (($JunkFile.Name.EndsWith(".cab")) -or ($JunkFile.Name.EndsWith(".xml")) -or ($JunkFile.Name.EndsWith(".msu")) -or ($JunkFile.Name.EndsWith("pkgProperties.txt")) -or ($JunkFile.Name.EndsWith("ini")))
        {
            Move-Item $JunkFile.FullName $PATCHCAB -Force -ErrorAction SilentlyContinue
            #Write-Host "Moving $JunkFile to $PATCHCAB" -ForegroundColor Cyan
            Continue
        }
        if ($JunkFile.Name -eq "patch")
        {
            Move-Item $JunkFile.FullName $PATCHCAB -Force -ErrorAction SilentlyContinue
            #Write-Host "Moving $JunkFile to $PATCHCAB" -ForegroundColor Magenta
            Continue
        }
    }
    catch
    {
        Write-Host "Error Processing ($JunkFile.Fullname)" -ForegroundColor DarkMagenta
    }
}

@wumb0 , Pardon me if this feature request doesn't make any sense. I am new to MS patch diffing and trying to learn from your blog and @OffByOneSecurity YouTube channel, and wanted to check if you would consider updating this script for Windows 11 patches?

I tried PatchExtract on Windows 11 (Build 22631) for March and April 2024 patches and noticed that it fails to extract the patches/deltas. The .CAB file does not contain patched binaries but just the manifest and catalog update files. I noticed another file, .PSF inside the MSU, which the expand.exe utility doesn't support.

Extracting the PSF file using PSFExtractor tool by @Secant1006 gives us the deltas for the patch in question. However, there are no reverse deltas anymore. It looks like Microsoft has made changes to the Windows 11 update process: https://techcommunity.microsoft.com/t5/windows-it-pro-blog/windows-11-cumulative-update-improvements-an-overview/ba-p/2842961

Would you consider updating this script for Windows 11 patches? Something like this?:

`$psffile = Get-ChildItem -Path $PATH -Filter "*.psf" | Select-Object -ExpandProperty Name

if ($psffile.ToUpper().EndsWith(".PSF")) {
$cabfile = Get-ChildItem -Path $PATH -Filter "Windows.cab" | Select-Object -ExpandProperty Name
iex("$EXPAND $cabfile -F:psfxml . | Out-Null )
$psfxml = Get-ChildItem -Path $PATH -Filter "*.xml" | Select-Object -ExpandProperty Name
iex(PSFExtractor.exe -v2 $psffile $psfxml . )
}`

But yes, Microsoft says, "Don’t crack open and use the individual files within the MSU. Why? The format may evolve as we continue to innovate on improving cumulative update fundamentals."

Extracting the PSF file using PSFExtractor tool by @Secant1006 gives us the deltas for the patch in question. However, there are no reverse deltas anymore. It looks like Microsoft has made changes to the Windows 11 update process: https://techcommunity.microsoft.com/t5/windows-it-pro-blog/windows-11-cumulative-update-improvements-an-overview/ba-p/2842961

I don't think reverse deltas are necessary in patch file. They can always be generated when installing patch.

Deltas are differences from one version to another, so we can define deltas as vectors. For example, suppose that A is the original version, B is current patched version, C is a newer version. Then, the patch from A to B (forward delta) is $\overrightarrow{AB}$, similarly, reverse delta is $\overrightarrow{BA}$.

Imagine we are on version B and we need to update to version C, so we need $\overrightarrow{BC}$. The patch can't include every deltas of every version to C as that would be huge and impossible, so it only has deltas from A to C. According to vector calculation, we have $\overrightarrow{BC}=\overrightarrow{BA}+\overrightarrow{AC}$. This is when reverse deltas are useful.

So how do we get reverse deltas? That would be super simple. When we installing patch from A to B using $\overrightarrow{AB}$, at one moment we have both version A and B, then we can calculate $\overrightarrow{BA}$. Similarly, $\overrightarrow{CA}$ can be calculated in the patch process as well. In concusion, there is no need to save reverse deltas in the patch as they can be easily calculated during patch process.

Extracting the PSF file using PSFExtractor tool by @Secant1006 gives us the deltas for the patch in question. However, there are no reverse deltas anymore. It looks like Microsoft has made changes to the Windows 11 update process: https://techcommunity.microsoft.com/t5/windows-it-pro-blog/windows-11-cumulative-update-improvements-an-overview/ba-p/2842961

I don't think reverse deltas are necessary in patch file. They can always be generated when installing patch.

Deltas are differences from one version to another, so we can define deltas as vectors. For example, suppose that A is the original version, B is current patched version, C is a newer version. Then, the patch from A to B (forward delta) is AB→, similarly, reverse delta is BA→.

Imagine we are on version B and we need to update to version C, so we need BC→. The patch can't include every deltas of every version to C as that would be huge and impossible, so it only has deltas from A to C. According to vector calculation, we have BC→=BA→+AC→. This is when reverse deltas are useful.

So how do we get reverse deltas? That would be super simple. When we installing patch from A to B using AB→, at one moment we have both version A and B, then we can calculate BA→. Similarly, CA→ can be calculated in the patch process as well. In concusion, there is no need to save reverse deltas in the patch as they can be easily calculated during patch process.

@Secant1006 , Thanks for a detailed and easy to understand explanation!