运行环境: Windows 7 32位  Visual Studio 2010

/**

名称：hookByCode

功能: 在某个API下钩子

参数：TCHAR * moduleName 模块名 TCHAR * funcName 函数名  PVOID hookProc 钩子函数

返回值：PBYTE 返回被下钩子的API的前5个字节 用于脱钩

**/

PBYTE hookByCode(TCHAR * moduleName,TCHAR * funcName,PVOID hookProc){

//获取API函数地址

PVOID APIAddr = getAPIAddress(moduleName,funcName);

//保存API前五个字节

BYTE pBuf[5] = {0,};

memcpy(pBuf,APIAddr,5);

//计算跳转距离

//目标位置

DWORD desPos = (DWORD)hookProc;

//源位置

DWORD srcPos = (DWORD)APIAddr+5;

DWORD jmpDistance = desPos-srcPos;

//取得可写权限

DWORD lpflOldProtect;

VirtualProtect(APIAddr,5,PAGE_READWRITE,&lpflOldProtect);

//设置跳转语句

memcpy((byte *)APIAddr+1,&jmpDistance,4);

*(BYTE *)APIAddr = 0xE9;

VirtualProtect(APIAddr,5,lpflOldProtect,&lpflOldProtect);

return pBuf;

}

HMODULE myload(LPCSTR lpLibFileName){

printf("惊喜吗！！！");

return 0;

}

void main(){

hookByCode(L"kernel32.dll",L"LoadLibraryA",myload);  //让LoadLibray被myload函数取代

HMODULE load = LoadLibraryW(L"kernel32.dll");

HMODULE (*loadW)(LPCSTR);

loadW = (HMODULE (*)(LPCSTR))GetProcAddress(load,"LoadLibraryA");

loadW("d");

}

结果图: