Pluto-Obfuscator

Pluto-Obfuscator is an obfuscator based on LLVM 12.0.1 by 34r7h4mn and za233.

Environment

This project was developed and tested on the following environment:

• Ubuntu 20.04.3 LTS
• Clang/LLVM 12.0.1
• CMake 3.16.3
• Ninja 1.10.0

You can also build this project on Windows and MacOS, or even merge it into Android NDK toolchain (tested on Android NDK r23).

Features

Pluto-Obfuscator encompasses multiple passes as follows (* indicates the most recommended passes):

• Control Flow Flattening (Ref: Obfuscator-LLVM)
• *Control Flow Flattening Enhanced (Chinese documentation)
• Bogus Control Flow (Ref: Obfuscator-LLVM)
• Instruction Substitution (Ref: Obfuscator-LLVM)
• Random Control Flow
• Variable Substitution
• String Encryption
• *Globals Encryption
• Trap Angr (Experimental)
• *MBA Obfuscation (Chinese documentation)

34r7hm4n: The documentation of this project is still lacking. I will work on it when I am available.

Usage

Build on Linux/Windows

The following commands work on both Linux and Windows:

mkdir -p build
cd build
cmake -G "Ninja" -DLLVM_ENABLE_PROJECTS="clang" \
    -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD="X86" \
    -DBUILD_SHARED_LIBS=On -DCMAKE_INSTALL_PREFIX="../install" ../llvm

ninja -j$(nproc)
ninja install

Build on MacOS

mkdir -p build
cd build
cmake -G "Ninja" -DLLVM_ENABLE_PROJECTS="clang" \
    -DCMAKE_BUILD_TYPE=Release \
    -DDEFAULT_SYSROOT=$(xcrun --show-sdk-path) \
    -DCMAKE_OSX_SYSROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX$(xcrun --show-sdk-version).sdk \
    -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" \
    -DCMAKE_INSTALL_PREFIX="../install" \
    ../llvm

ninja -j$(sysctl -n hw.logicalcpu)
ninja install

Compile with the Most Recommended Obfuscation

// TODO -s -mllvm -mba -mllvm -mba-prob=50 -mllvm -fla-ex -mllvm -gle

Filter Mode

In case you just want to obfuscate specific functions, Pluto-Obfuscator also provides a filter mechanism using annotation, to help you specify which functions should or should not be obfuscated.

To enable this mechanism, you should pass -mllvm -filter-mode=include or -mllvm -filter-mode=exclude to clang as an argument.

• -filter-mode=include: only those functions with "include" annotation will be obfuscated.
• -filter-mode=exclude: ignore those functions with "exclude" annotation.
• -filter-mode=none: all functions will be processed. (by defualt)

For example:

clang++ TestFilter.cpp -mllvm -fla -mllvm -filter-mode=include -o TestFilter_include    # include mode
clang++ TestFilter.cpp -mllvm -fla -mllvm -filter-mode=exclude -o TestFilter_include    # exclude mode
clang++ TestFilter.cpp -mllvm -fla -mllvm -o TestFilter_include    # default mode

Following is a self-explanatory snippet showing how to annonate functions. In this case, only foo1 will be obfuscated in include mode. Only foo2 will be ignored in exclude mode. And foo3 will always be obfuscated:

#define FUNC_INCLUDE __attribute__((annotate("include")))
#define FUNC_EXCLUDE __attribute__((annotate("exclude")))

FUNC_INCLUDE
void foo1(){ }

FUNC_EXCLUDE
void foo2(){ }

void foo3(){ }

int main(){
    foo1();
    foo2();
    foo3();
}

Test suite

IMPORTANT: If you would like to improve this project by creating pull requests, please make sure your modified code can pass the tests as follows. Issues and pull requests about the most recommended passes will be prioritized.

Quick Test on AES

Usage: ./fast-check [your-passes] (e.g., ./fast-check.sh mba mba-prob=50 fla-ex gle).

See fast-check.sh and test/aes.

Test on libsecp256k1

Usage: ./check.sh [your-passes] (e.g., ./check.sh mba mba-prob=50 fla-ex gle)

Generally, it will cost several minutes to be done, much slower compared to AES test.

Passed Parameters:

• Flattening: fla
• FlatteningEnhanced: fla-ex
• Substitution: sub
• GlobalsEncryption: gle
• MBAObfuscation: mba mba-prob=100
• FullProtection (HIGHLY RECOMMENDED): mba mba-prob=50 fla-ex gle

See check.sh and test/secp256k1.