README.md

Description

I have found out many people want to know how to use WriteProcessMemory due to the fact of writing memory trainers to cheat in video games in such. I have seen that PSC did not have a very good example of this so I guess ill just post this small code snipet! This is the non-mfc version.

More Info

This will write a couple of bytes to a address in the running memory of a process. This will not work in MFC. I will post a MFC version soon. ~ Revised 3-20-04, cleaned up error handling, couple of bugs and etc.

Submitted On
By	fritz0x00
Level	Beginner
User Rating	4.9 (34 globes from 7 users)
Compatibility	C++ (general), Microsoft Visual C++, Borland C++
Category	Coding Standards
World	C / C++
Archive File

Source Code

#include <windows.h>
void main()
{
	HWND hWnd = FindWindow(0, "MSN Messenger"); //** Define the window we are looking for
	if(hWnd == NULL) //** If window is not found, Error cannot find window!
	{
		MessageBox(0, "Error cannot find window!", "Error!", MB_OK + MB_ICONERROR);
	}
	else
	{
		DWORD proc_id;
		//** Declares DWORD proc_id which will later hold
		//** the handle for the process ID which we hook
		//** the process with
		GetWindowThreadProcessId(hWnd, &proc_id);
		//** Gets process ID by window caption, stores
		//** the recived process id in 'proc_id'
		//** which we declared earlier with:
		//** 'DWORD proc_id;
		HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, proc_id);
		//** Opens the process with
		//** by using the stored ID
		//** in 'proc_id'
		if(!hProcess) //** If cannot 'OpenProcess', then it displays the error message
		{
			MessageBox(NULL, "Cannot open process!", "Error!", MB_OK + MB_ICONERROR);
		}
		else
		{
			//** Below; The data to write to the address which we later state
			BYTE newdata[]={0x72, 0x65, 0x64, 0x70, 0x6F, 0x74, 0x69, 0x6F, 0x6E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
			DWORD newdatasize = sizeof(newdata);
			//** Below; We use WriteProcessMemory to our stored process, 'hProcess'
			//** and writes 'newdata' to our address '(LPVOID)0x5C6600'
			if(WriteProcessMemory(hProcess, (LPVOID)0x5C6600, &newdata, newdatasize, NULL))
			{
				//** If we write the memory successfully, we let the user know
				MessageBox(NULL, "WriteProcessMemory is a success!", "Success!", MB_OK + MB_ICONINFORMATION);
				//** Alerts user that it has written
			}
			else
			{
				//** If we cant write the memory to our process, we notify
				//** the user with the following error message;
				MessageBox(NULL, "Error cannot WriteProcessMemory!", "Error!", MB_OK + MB_ICONERROR);
			}
			//** Closes process after we write the memory,
			//** helps stop memory leaks
			CloseHandle(hProcess);
		}
	}
}