从托管代码中调用Hook LoadLibrary

Question

我们想挂钩调用LoadLibrary以下载未找到的程序集.我们有一个处理托管程序集的ResolveAssembly处理程序,但我们还需要处理非托管程序集.

我们尝试通过"编写Microsoft Windows编程应用程序"中指定的技术重写import表来挂钩LoadLibrary调用,但是当我们调用WriteProcessMemory()时,我们得到一个权限被拒绝错误(998).(是的,我们正在使用提升的私人运行)

在加载CLR时是否有人成功重写了import表？谁能指出我正确的方向？

更新:我们解决了权限被拒绝的问题,但现在当我们迭代混合程序集的Imports表(托管+非托管)时,我们找到的唯一条目是mscoree.dll.有谁知道如何找到原生进口？(我们在C++/CLI中工作).

Answer 1

我已成功连接托管代码.但是,我是通过将一个非托管DLL注入远程进程并让它重写DllMain中的导入表来实现的.您可能想要考虑这种方法.

这是我的挂钩功能:

//structure of a function to hook
struct HookedFunction {
public:
    LPTSTR moduleName;
    LPTSTR functionName;
    LPVOID newfunc;
    LPVOID* oldfunc;
};

BOOL Hook(HMODULE Module, struct HookedFunction Function) {
    //parse dos header
    IMAGE_DOS_HEADER* dos_header = (IMAGE_DOS_HEADER*)Module;
    if (dos_header->e_magic != IMAGE_DOS_SIGNATURE) return 0; //not a dos program

    //parse nt header
    IMAGE_NT_HEADERS* nt_header = (IMAGE_NT_HEADERS*)(dos_header->e_lfanew + (SIZE_T)Module);
    if (nt_header->Signature != IMAGE_NT_SIGNATURE) return 0; //not a windows program

    //optional header (pretty much not optional)
    IMAGE_OPTIONAL_HEADER optional_header = nt_header->OptionalHeader;
    if (optional_header.Magic != IMAGE_NT_OPTIONAL_HDR32_MAGIC) return 0; //no optional header

    IMAGE_IMPORT_DESCRIPTOR* idt_address = (IMAGE_IMPORT_DESCRIPTOR*)(optional_header.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress + (SIZE_T)Module);
    if (!optional_header.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].Size) return 0; //no import table

    //enumerate the import dlls
    BOOL hooked = false;
    for(IMAGE_IMPORT_DESCRIPTOR* i = idt_address; i->Name != NULL; i++)
        //check the import filename
        if (!_stricmp(Function.moduleName, (char*)(i->Name + (SIZE_T)Module)))
            //enumerate imported functions for this dll
            for (int j = 0; *(j + (LPVOID*)(i->FirstThunk + (SIZE_T)Module)) != NULL; j++)
                //check if the function matches the function we are looking for
                if (!_stricmp(Function.functionName, (char*)(*(j + (SIZE_T*)(i->OriginalFirstThunk + (SIZE_T)Module)) + (SIZE_T)Module + 2) )) {
                    //replace the function
                    LPVOID* memloc = j + (LPVOID*)(i->FirstThunk + (SIZE_T)Module);
                    if (*memloc != Function.newfunc) { //not already hooked
                        DWORD oldrights;
                        DWORD newrights = PAGE_READWRITE;
                        VirtualProtect(memloc, sizeof(LPVOID), newrights, &oldrights);
                        if (Function.oldfunc && !*Function.oldfunc)
                            *Function.oldfunc = *memloc;
                        *memloc = Function.newfunc;
                        VirtualProtect(memloc, sizeof(LPVOID), oldrights, &newrights);
                    }
                    hooked = true;
                }

    return hooked;
}

Answer 2

应该工作,但尝试使用绕道(或免费的N-CodeHook)代替.
Detours几乎是用于检测Win32二进制文件的事实上的方式.