IRobs

A simple proof of concept for Out-Of-Tree LLVM Pass binary target obfuscation.

This LLVM Pass splits BasicBlocks and insert some junk instructions in the new branch, making more complex the function graph, but without modifiying the original execution flow.

There is a lot of room for improvement. Do not use this project for production! This is easily defeated!

Before and after IRobs pass

Before

After

Dependencies

Download stable version of LLVM

* git clone https://github.com/llvm-mirror/llvm.git
* git checkout stable

Download clang into the cloned LLVM directory

* git clone --depth=1 --branch=google/stable https://github.com/llvm-mirror/clang

Then compile LLVM. Building LLVM takes a lot of memory so configure your cmake accordingly! My building steps are the following:

* cd [where_llvm_was_downloaded] && mkdir build && cd build 
* cmake .. -DLLVM_USE_LINKER=gold -DCMAKE_BUILD_TYPE:STRING=Release -DLLVM_TARGETS_TO_BUILD:STRING="X86;ARM;AArch64" -DLLVM_INSTALL_UTILS=ON -DCMAKE_INSTALL_PREFIX=$HOME/llvm-stable
* make -j [n-1] # which n is the number of processors 
* be patient
* make install

LLVM should be installed at $HOME/llvm-stable

Compile IRobs