阻止Spy++之类的工具捕捉软件窗口

 我以前用Spy++能轻易捕捉360软件界面,除了一些应用DHTML制作的窗体.昨天我再用Spy++捕捉的时候捕捉不到了,甚至连最外围的对话框都捕捉不到,显然是做了类似拦截API的处理.下面我也模拟一下这种效果,让自己的程序窗口不能被捕捉.
Spy++之类的程序一般通过API函数WindowFromPoint和ChildWindowFromPoint来获取指定位置的窗口句柄。拦截一下WindowFromPoint函数,如果捕捉到的是自己程序的窗口,而且实施捕捉的进程不是自己程序的进程,那就直接返回NULL(这样自己的程序捕捉自己的窗口就不会受影响).拦截API我直接用微软的Detour库,使用起来方便.

由于是拦截所有进程地址空间的WindowFromPoint函数,我借助于全局WH_SHELL钩子，因此拦截操作放在一单独的DLL项目中.先封装一下Detour操作CInterceptSpyFun类:

class CInterceptSpyFun{private:    //是否已经拦截    BOOL  m_bIntercepted;public:    //保存要屏蔽WindowFromPoint函数的进程ID    static  DWORD  m_dwValidProcessID;  public:    CInterceptSpyFun( );    ~CInterceptSpyFun( );    BOOL  IsIntercepted()     {        return this->m_bIntercepted;    }    /*    * 拦截操作    * dwValidProcessID: 待屏蔽WindowFromPoint函数的进程ID    * 返回拦截成功与否    */    BOOL  Intercept( DWORD dwValidProcessID  );    /*    * 取消拦截,还原成原先的操作    */    void    UnIntercept();};

DWORD  CInterceptSpyFun::m_dwValidProcessID   =  0;//让Real_WindowFromPoint指针指向实际上的WindowFromPoint函数地址DETOUR_TRAMPOLINE( HWND WINAPI Real_WindowFromPoint( POINT pt ), WindowFromPoint );/** 自定义WindowFromPoint函数的处理*/HWND WINAPI Mine_WindowFromPoint( POINT pt ){    //调用实际上的WindowFromPoint函数,取得窗口句柄    HWND  hWnd =  Real_WindowFromPoint( pt );    //获取窗口所属的进程ID    DWORD  dwProcessID(0);    ::GetWindowThreadProcessId( hWnd, &dwProcessID );    if( ( CInterceptSpyFun::m_dwValidProcessID == dwProcessID ) && ( ::GetCurrentProcessId() != CInterceptSpyFun::m_dwValidProcessID ) )    {    //如果窗口属于指定的进程并且是被不是指定进程的其他进程调用WindowFromPoint访问时,返回NULL        return NULL;    }    return hWnd;}CInterceptSpyFun::CInterceptSpyFun( ){    m_bIntercepted  =  FALSE;}CInterceptSpyFun::~CInterceptSpyFun( ){}BOOL  CInterceptSpyFun::Intercept( DWORD dwValidProcessID ){    CInterceptSpyFun::m_dwValidProcessID   =  dwValidProcessID;    //Detour库拦截处理    m_bIntercepted  =  DetourFunctionWithTrampoline( (PBYTE)Real_WindowFromPoint,  (PBYTE)Mine_WindowFromPoint );    return m_bIntercepted;}void    CInterceptSpyFun::UnIntercept(){    if( m_bIntercepted )    {        //取消拦截        DetourRemove( (PBYTE)Real_WindowFromPoint,(PBYTE)Mine_WindowFromPoint );        m_bIntercepted  =  FALSE;    }}

dwValidProcessID(要拦截WindowFromPoint函数的进程ID)需要在LoadLibrary之后,安装钩子之前传递,并且需要保存到共享节中以达到在所有的进程中数据共享的目的. 
#pragma  data_seg(".unspy")
HHOOK   hHook   =   NULL;  
DWORD  dwValidProcessID  =  0;
#pragma  data_seg()
#pragma comment(linker,"/section:.unspy,rws")

HOOK句柄和dwValidProcessID  都保存到共享节”.unspy”中。

设置dwValidProcessID  的导出函数：
extern"C" __declspec( dllexport ) void SetValidProcessID( DWORD  dwProcessID )
{
 dwValidProcessID   =  dwProcessID;
}

声明拦截类的全局变量:
CInterceptSpyFun  interceptSpy;  
HMODULE   hDllModule   =  NULL;  //保存DLL模块句柄

SHELL钩子处理:

LRESULT CALLBACK CustomShellProc (int nCode, WPARAM wParam, LPARAM lParam){        if( !interceptSpy.IsIntercepted() )    {  //拦截API        interceptSpy.Intercept( dwValidProcessID );    }    return ::CallNextHookEx( hHook, nCode, wParam, lParam );}extern"C" __declspec( dllexport ) void InstallHook( ){    hHook = ::SetWindowsHookEx( WH_SHELL , CustomShellProc ,(HINSTANCE)hDllModule, 0 );}extern"C" __declspec( dllexport ) void UninstallHook(){        if( hHook != NULL )    {        ::UnhookWindowsHookEx( hHook );    }    hHook = NULL;}

取消拦截操作应在卸载DLL的时候:
BOOL APIENTRY DllMain( HMODULE hModule,  DWORD  ul_reason_for_call,   LPVOID lpReserved  )
{
 hDllModule   =   hModule;
 switch (ul_reason_for_call)
 {
 case DLL_PROCESS_ATTACH: 
  break;
 case DLL_THREAD_ATTACH:
  break;
 case DLL_THREAD_DETACH:
  break;
 case DLL_PROCESS_DETACH:
  {
      interceptSpy.UnIntercept();
  }
  break;
 }

    return TRUE;
}

至此,DLL部分已经完成.在需要屏蔽WindowFromPoint函数的程序中需加载该DLL,调用DLL的SetValidProcessID,将当前的进程ID传入,随后安装钩子:
m_hInstance  = ::LoadLibrary(_T("AvoidSpyLib.dll"));
  if ( m_hInstance == NULL )
  {
   ::MessageBox(NULL,_T("LoadLibrary Failed"),_T(""),MB_OK);
  }

  if( m_hInstance == NULL )
   return 0;
 
  typedef void (*PSetValidProcessID)( DWORD  dwProcessID );
  PSetValidProcessID pSetFunc;
  pSetFunc = (PSetValidProcessID)::GetProcAddress( m_hInstance , "SetValidProcessID");
  if ( pSetFunc != NULL )
  {
   (*pSetFunc)( ::GetCurrentProcessId() );
  }

  typedef void (*PInstallHook)( );
  PInstallHook pInstallFunc;
  pInstallFunc = (PInstallHook)::GetProcAddress( m_hInstance , "InstallHook");
  if ( pInstallFunc != NULL )
  {
    (*pInstallFunc)();
}
//卸载钩子
if( m_hInstance != NULL )
{
   typedef void (*PUninstallHook)( );
   PUninstallHook pFunc;
   pFunc = (PUninstallHook)::GetProcAddress( m_hInstance , "UninstallHook");
   if ( pFunc != NULL )
   {
    (*pFunc)();
   }

   ::FreeLibrary( m_hInstance );
}

全部完工,运行了一下,呵呵,和360软件的效果一样,Spy++再也捕捉不到界面的任何东西了.