C++ Dll Injection
c++, code-injection, dll, process
Solution
You don't have to write a DLL to change another process's memory at a fixed address. You can use `WriteProcessMemory()`.
However... The way to inject a DLL into another process is the following...
Use `VirtualAllocEx()` to allocate the length of the file path to the DLL inside the target process's memory... This is like remotely doing a `malloc`.
Use `WriteProcessMemory()` to copy the file path to the DLL into what was returned from the previous step. This is like remotely doing a `strcpy`.
Use `CreateRemoteThread()`. You can point it at `LoadLibrary()` as the entry point and the file path from steps 1 and 2 as the argument. That's a bit hacky, to be honest, but if you are injecting a DLL you're already being quite hacky. Another technique would be to use steps 1 & 2 to load some machine code into the remote proceess and point it at that.
Keep in mind that this technique is a great way to destabilize the target process. In particular, this isn't something I'd do in a product that ends up getting shipped to others.
Problem
I would really appreciate your help in this. I have been trying to get a Dll injected into a remote process and do a few changes inside it, the problem I'm encountering right now is i don't know how to get this going. So first, here is my piece of code that I have developed so far: dllmain.cpp ``` #include <windows.h> #include <stdio.h> BOOL APIENTRY DllMain (HINSTANCE hInst /* Library instance handle. */ , DWORD reason /* Reason this function is being called. */ , LPVOID reserved /* Not used. */ ) { switch (reason) { case DLL_PROCESS_ATTACH: MessageBox (0, "From DLL\n", "Process Attach", MB_ICONINFORMATION); break; case DLL_PROCESS_DETACH: MessageBox (0, "From DLL\n", "Process Detach", MB_ICONINFORMATION); break; case DLL_THREAD_ATTACH: MessageBox (0, "From DLL\n", "Thread Attach", MB_ICONINFORMATION); break; case DLL_THREAD_DETACH: MessageBox (0, "From DLL\n", "Thread Detach", MB_ICONINFORMATION); break; } return TRUE; } ``` It simply displays a message box depending on the conditions it meets. Now what I would like my Dll to do is, after being injected into the remote process, I would like it to write a memory location and change it's value. Data type: Unsigned Short Int Memory location: 0041D090 I hope everything is clear, Thank you for your patience, help is appreciated.