// _remotethreaddemo.cpp : Defines the entry point for the console application.
// Author:秋镇菜

#include "stdafx.h"
#include "windows.h"

// ========== 定义一个代码结构,本例为一个对话框============
struct MyData
{
 char sz[64]; // 对话框显示内容
 DWORD dwMessageBox; // 对话框的地址
};

// ========== 远程线程的函数 ==============================
DWORD __stdcall RMTFunc(MyData *pData)
{
 typedef int(__stdcall*MMessageBox)(HWND,LPCTSTR,LPCTSTR,UINT);
 MMessageBox MsgBox = (MMessageBox)pData->dwMessageBox;
 MsgBox(NULL, pData->sz, NULL, MB_OK);
 return 0;
}
int main(int argc, char* argv[])
{
// ===== 获得需要创建REMOTETHREAD的进程句柄 ===============================
 HWND hWnd = FindWindow("notepad", NULL); // 以NOTEPAD为例
 DWORD dwProcessId;
 ::GetWindowThreadProcessId(hWnd, &dwProcessId);
 HANDLE hProcess = OpenProcess(
        PROCESS_ALL_ACCESS,
        FALSE,
        dwProcessId);

// ========= 代码结构 ================================================
 MyData data;
 ZeroMemory(&data, sizeof (MyData));
 strcat(data.sz, "对话框的内容.");
 HINSTANCE hUser = LoadLibrary("user32.dll");
 if (! hUser)
 {
  printf("Can not load library.\n");
  return 0;
 }
 data.dwMessageBox = (DWORD)GetProcAddress(hUser, "MessageBoxA");
 FreeLibrary(hUser);
 if (! data.dwMessageBox)
  return 0;

// ======= 分配空间 ===================================================
 void *pRemoteThread
  = VirtualAllocEx(hProcess, 0,
      1024*4, MEM_COMMIT|MEM_RESERVE,
      PAGE_EXECUTE_READWRITE);
 if (! pRemoteThread)
  return 0;
 if (! WriteProcessMemory(hProcess, pRemoteThread, &RMTFunc, 1024*4, 0))
  return 0;

 MyData *pData
  = (MyData*)VirtualAllocEx(hProcess, 0,
      sizeof (MyData), MEM_COMMIT,
      PAGE_READWRITE);
 if (!pData)
  return 0;

 if (! WriteProcessMemory(hProcess, pData, &data, sizeof (MyData), 0))
  return 0;

// =========== 创建远程线程 ===========================================
 HANDLE hThread
  = CreateRemoteThread(hProcess, 0,
       0, (LPTHREAD_START_ROUTINE)pRemoteThread,
       pData, 0, 0);
 if (! hThread)
 {
  printf("远程线程创建失败");
  return 0;
 }
 CloseHandle(hThread);
 VirtualFreeEx(hProcess, pRemoteThread, 1024*3, MEM_RELEASE);
 VirtualFreeEx(hProcess, pData, sizeof (MyData), MEM_RELEASE);
 CloseHandle(hProcess);
 printf("Hello World!\n");
 return 0;
}