#include <stdio.h> #include <windows.h> #include <Dbghelp.h> #pragma comment(lib,"Dbghelp.lib") #pragma comment(lib,"User32.lib") typedef int (__stdcall *OLD_MessageBox)( HWND hWnd, LPCTSTR lpText, LPCTSTR lpCaption,UINT uType ); OLD_MessageBox g_procOldMessageBox = NULL; int __stdcall HOOK_MessageBox( HWND hWnd, LPCTSTR lpText, LPCTSTR lpCaption,UINT uType) { printf("%s\t%d\r\n",__FUNCTION__,__LINE__); if (NULL != g_procOldMessageBox) return g_procOldMessageBox(hWnd,lpText,TEXT("不好意思,hook到了!"),uType); else return MessageBox(hWnd,lpText,lpCaption,uType); ; } int replace_IAT(const char *pDllName,const char *pApiName,void ** OldApiAddr,void * NewApiAddr,bool bReplace) { HANDLE hProcess = ::GetModuleHandle (NULL); DWORD dwSize = 0; PIMAGE_IMPORT_DESCRIPTOR pImageImport = (PIMAGE_IMPORT_DESCRIPTOR)ImageDirectoryEntryToData(hProcess,TRUE, IMAGE_DIRECTORY_ENTRY_IMPORT,&dwSize); if (NULL == pImageImport) return 1; PIMAGE_IMPORT_BY_NAME pImageImportByName = NULL; PIMAGE_THUNK_DATA pImageThunkOriginal = NULL; PIMAGE_THUNK_DATA pImageThunkReal = NULL; while (pImageImport->Name) { if (0 == lstrcmpiA((char*)((PBYTE)hProcess+pImageImport->Name),pDllName)) { break; } ++pImageImport; } if (! pImageImport->Name) return 2; pImageThunkOriginal = (PIMAGE_THUNK_DATA)((PBYTE)hProcess+pImageImport->OriginalFirstThunk ); pImageThunkReal = (PIMAGE_THUNK_DATA)((PBYTE)hProcess+pImageImport->FirstThunk ); while (pImageThunkOriginal->u1.Function) { if ((pImageThunkOriginal->u1.Ordinal & IMAGE_ORDINAL_FLAG) != IMAGE_ORDINAL_FLAG) { pImageImportByName = (PIMAGE_IMPORT_BY_NAME)((PBYTE)hProcess+pImageThunkOriginal->u1.AddressOfData ); if (0 == lstrcmpiA(pApiName,(char*)pImageImportByName->Name)) { MEMORY_BASIC_INFORMATION mbi_thunk; VirtualQuery(pImageThunkReal, &mbi_thunk, sizeof(MEMORY_BASIC_INFORMATION)); VirtualProtect(mbi_thunk.BaseAddress,mbi_thunk.RegionSize, PAGE_READWRITE, &mbi_thunk.Protect); if (true == bReplace) { *OldApiAddr = (void*)pImageThunkReal->u1.Function; pImageThunkReal->u1.Function = (DWORD)(NewApiAddr); } else { pImageThunkReal->u1.Function = (DWORD)(*OldApiAddr); *OldApiAddr = NULL; } DWORD dwOldProtect; VirtualProtect(mbi_thunk.BaseAddress, mbi_thunk.RegionSize, mbi_thunk.Protect, &dwOldProtect); break; } } ++pImageThunkOriginal; ++pImageThunkReal; } return 0; } int _tmain(int argc, _TCHAR* argv[]) { replace_IAT("User32.dll","MessageBoxW",(void**)&g_procOldMessageBox,HOOK_MessageBox,true); MessageBox(NULL,TEXT("EnumIAT User32.dll MessageBoxW true;"),TEXT(""),MB_OK); replace_IAT("User32.dll","MessageBoxW",(void**)&g_procOldMessageBox,HOOK_MessageBox,false); MessageBox(NULL,TEXT("EnumIAT User32.dll MessageBoxW false;"),TEXT("UnHook!"),MB_OK); return getchar(); return 0; }