Squalr / Self-Modifying-Code

C++ Self Modifying Code (Self Assembing/Disassembling)

SelfHackingApp

This repo contains an example of how to create self-modifying code in C++. This works by allowing code to rewrite itself using injected x86/x64 assembly instructions.

This code is 100% cross-platform, however this repo is currently only set up for Widows + Visual Studio. I wrote about this repo here: https://medium.com/squallygame/how-we-wrote-a-self-hacking-game-in-c-d8b9f97bfa99

Feel free to submit a pull request with a CMake solution that works on Linux/OSX/Windows.

Example:

NO_OPTIMIZE
int hackableRoutineTakeDamage(int health, int damage)
{
    // This is the code we want to be hackable by the user
    HACKABLE_CODE_BEGIN();
    health -= damage;
    HACKABLE_CODE_END();

    HACKABLES_STOP_SEARCH();

    if (health < 0)
    {
        health = 0;
    }

    return health;
}
END_NO_OPTIMIZE

Which can be modified via:

auto funcPtr = &hackableRoutineTakeDamage;
std::vector<HackableCode*> hackables = HackableCode::create((void*&)funcPtr);

HackableCode* hackableCode = hackables[0];

// Disable taking damage by injecting a 'nop' over the original 'health -= damage;' code. Remaining bytes are filled with 'nops'
hackableCode->applyCustomCode("nop")