Free open-source obfuscator for Mono

BitMono

BitMono is a free open-source C# obfuscator that in most cases works only with Mono - well known as a fork of .NET framework (which runs popular platforms such as Unity, etc), you can still use this for a whole .NET, but be careful that something working not as intentional, because the main target of the this project is Mono. Which uses AsmResolver for assembly manipulation (not a dnlib as you might already think). If you have any questions/issues please let me know there. You can install the latest version of BitMono here.

Usability

BitMono breaks the most popular tools using just one packer, such as:

• dnSpy;
• dnlib;
• AsmResolver;
• MonoCecil;
• ILSpy;
• PEBear;
• DetectItEasy;
• CFF Explorer
• Perhaps, some dumpers?
• and many, many more...

So, if you will add more protection to the file, I think it would seem like total magic. :D

Documentation

Read the docs to read protection, functionality, and more.

How your app will look since BitMono obfuscation - just in a few words

• Looks like C++ application but is an actual C# application;
• Crash of decompilers when analyzing types;
• Broken decompilers;
• Broken IL Code;
• Invisible types;
• No code

Features

• StringsEncryption
• UnmanagedString (based on existing protection)
• BitDotNet (based and improved on existing protection)
• BitMethodDotnet (based and improved on existing protection)
• DotNetHook (based on existing protection)
• CallToCalli
• ObjectReturnType
• NoNamespaces
• FullRenamer
• AntiDebugBreakpoints
• AntiDecompiler
• BitDateTimeStamp
• BitMono

Usage

Using CLI

BitMono.CLI <path to file>/drag-and-drop

Always drop dependencies in libs directory in the same path where file for obfuscation is located

Your obfuscation directory structure will look something like this:

specially_created_folder_for_obfuscation/
├─ your_app.exe
└─ libs/
  ├─ ImportantLibrary.dll
  ├─ SuperImportantLibrary.dll
  └─ ...

Copy all libraries (.dll) from the building application folder and paste them into the libs directory (if it doesn't exist yet create it), or even create the libs directory yourself with a custom name for example - myLibs, and then specify it in BitMono, however, if you will use libs then by default BitMono looking for a libs directory, so it will save your time.

Using CLI Commands

  -f, --file         Required. Set file path.

  -l, --libraries    Set libraries path.

  -o, --output       Set output path.

  --help             Display this help screen.

  --version          Display version information.

Basic example

$ BitMono.CLI -f C:\specially_created_folder_for_obfuscation/your_app.exe -l specially_created_folder_for_obfuscation/libs

In case when you already have a directory with the name libs (specially_created_folder_for_obfuscation\libs) BitMono will catch it automatically, so, you don't need to specify it anymore, but you can in case if you made another directory with libs somewhere on the disk or even just for "visibility".

$ BitMono.CLI -f C:\specially_created_folder_for_obfuscation/your_app.exe

Specify custom libs directory

$ BitMono.CLI -f C:\specially_created_folder_for_obfuscation/your_app.exe -l C:\mythings\obfuscation\superLibsDirectory

Specify file, libs and output. If output directory doesn't exist BitMono will create it automatically and even open it on the top of the screen, if you want you can disable opening of the directory on the of top of the screen in obfuscation.json - and set OpenFileDestinationInFileExplorer to false.

$ BitMono.CLI -f C:\specially_created_folder_for_obfuscation/your_app.exe -l C:\mythings\obfuscation\superLibsDirectory -o C:\specially_created_folder_for_obfuscation/output

Want more? Simply read the docs.

Detailed build status

Branch	AppVeyor
main
dev

Credits

0x59R11 for his acquaintance in big part of BitDotNet that breaks files for mono executables!

Gazzi for his help that me asked a lot!

Elliesaur for her acquaintance in DotNetHook that hooks methods.

Weka for his advices, help and motivation.

MrakDev for the acquaintance in UnmanagedString.

ConfuserEx and their Forks for most things that I watched for the architecture of BitMono and the obfuscator engine as an application and solving plenty of User solutions which I would be knew in the very long future after much fail usage of BitMono and reports by other Users. Day-by-day I'm looking for something interesting there to improve myself in knowledge and BitMono also.

OpenMod Definitely, openmod inspired this project a lot with services and clean code, extensive similar things to openmod.

Kao and his blogs thanks a lot of these blogs.

drakonia for her costura decompressor.