C++ Shellcode Injection

About this project

We will understand how to inject the shellcode we have written using the "CreateRemoteThread" api.

Requirements

• Beginner assembly x86 knowledge
• C/C++ knowledge
• CMAKE knowledge (optional for build this project)

About shellcode in this project

unsigned char shellcode[] = {
    0x6A, 0x00,                   // push   0x0             -> UINT    uType
    0x68, 0xFF, 0xFF, 0xFF, 0x00, // push   0xffffff        -> LPCTSTR lpCaption
    0x68, 0xFF, 0xFF, 0xFF, 0x00, // push   0xffffff        -> LPCTSTR lpText
    0x6A, 0x00,                   // push   0x0             -> HWND    hWnd
    0xB8, 0xFF, 0xFF, 0xFF, 0x00, // mov    eax,0xffffff    -> MessageBoxA PTR
    0xFF, 0xD0,                   // call   eax
    0x31, 0xC0,                   // xor    eax,eax
    0xC3                          // ret
};

This shellcode we wrote calls a function that takes 4 parameters. We want to see a message box in target app. When we examine the "messagebox" api, our shellcode is compatible. Click for more information about MessageBoxA

How to build&run this project

git clone https://github.com/byRespect/cpp-shellcode-inject
cd cpp-shellcode-inject
cmake .
make
wine shellcodetest.exe

⚠️ : The project must be compiled in x86 architecture. And the target application must be in x86 architecture.

References

• defuse.ca for assembly to byte or byte to assembly.