bool Hook(char* lpLib, char* lpModule, int iBytes, BYTE *ucDstAddress, HOOK_ADDR *hook) {
   HMODULE hLib;
 
   hLib = GetModuleHandle(lpLib);
   if (hLib) {
      BYTE *ucSrcAddress;
      ucSrcAddress = (BYTE *) GetProcAddress(hLib, lpModule);
 
      if (ucSrcAddress) {
         DWORD ulOldProtect;
		 if ((Buffer = (BYTE *) malloc(iBytes + 5)) == NULL) return 0;
         if (VirtualProtect((void *) Buffer, iBytes + 5, PAGE_EXECUTE_READWRITE, &ulOldProtect) == 0) return 0;
 
         memcpy(Buffer, ucSrcAddress, iBytes);
 
         Buffer += iBytes;
         *Buffer = 0xE9;
         Buffer++;
         *((signed int *) Buffer) = ucSrcAddress - Buffer + (iBytes - 5) + 1;
 
         if (VirtualProtect((void *) ucSrcAddress, iBytes, PAGE_EXECUTE_READWRITE, &ulOldProtect) == 0) return 0;
 
         hook->ulDstModAddr = (unsigned long) ucDstAddress;
         *ucSrcAddress = 0xE9;
         ucSrcAddress++;
         *((signed int *) ucSrcAddress) = ucDstAddress - ucSrcAddress - 4;
 
         FlushInstructionCache(GetCurrentProcess(), NULL, NULL);
 
         strcpy(hook->lpLib, lpLib);
         strcpy(hook->lpModule, lpModule);
         hook->uiBytes = iBytes;
         hook->ulSrcModAddr = (unsigned long) ucSrcAddress;
 
         return true;
	  }
   }
   return false;
}
 

  ret = Hook("psapi", "EnumProcesses", 7, (BYTE *) EnumProcesses_Hook, &addr);
  pEnumProcesses = (BOOL (__stdcall *)(DWORD*, DWORD, DWORD*)) (Buffer - 7 - 1);