进程注入器在 CreateRemoteThread 上崩溃

Question

为了检测工程的目的，我在 C 中创建了一个进程 DLL 注入器，它似乎对我在 shell 中生成的测试进程非常有效（可能是因为它们在同一条路径上，或者与非-shells 和 printf) 但每当我在随机进程上测试它时，它会在 CreateRemoteThread 步骤中崩溃所述进程，想知道你们是否可以提供帮助谢谢。

如果有帮助的话，这是我使用的命令 (Bash)： ./ProcessInjector.exe [PID] C:\Users\wsam\Documents\Process-Injection\bad_dll.dll

编辑：我注意到如果我取出 bad_dll.dll while 循环中的所有代码，它会成功创建线程并且不会使进程崩溃，这是为什么？

ProcessInjector.c

#include <windows.h>
#include <string.h>
#include <stdio.h>
#include <tlhelp32.h>

int main(int argc, char* argv[]){
    char dllPath[MAX_PATH];
    strcpy(dllPath, argv[2]);

    printf("Victim PID      : %s\n", argv[1]);
    // use full or relative path
    printf("DLL to inject   : %s\n", argv[2]);

    // get Handle from proc id
    HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, atoi(argv[1]));
    if (hProcess == NULL) {
        printf("[---] Failed to open process %s.\n", argv[1]);
        return 1;
    }

    printf("Press Enter to attempt DLL injection.");
    getchar();

    // Allocate memory for DLL's path
    LPVOID dllPathAlloc = VirtualAllocEx(hProcess, NULL, strlen(dllPath), MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE);
    if(dllPathAlloc == NULL){
        printf("[---] VirtualAllocEx unsuccessful.\n");
        getchar();
        return 1;
    }

    // Write path to memory
    BOOL pathWrote = WriteProcessMemory(hProcess, dllPathAlloc, dllPath, strlen(dllPath), NULL);
    if(!pathWrote){
        printf("[---] WriteProcessMemory unsuccessful.\n");
        getchar();
        return 1;
    }

    // returns pointer to LoadLibrary address, same in every process.
    LPVOID loadLibraryAddress = (LPVOID)GetProcAddress(GetModuleHandle("kernel32.dll"), "LoadLibraryA");
    if(loadLibraryAddress == NULL){
        printf("[---] LoadLibrary not found in process.\n");
        getchar();
        return 1;
    }

    // creates remote thread and start mal dll
    HANDLE remoteThread = CreateRemoteThread(hProcess, NULL, 0, (LPTHREAD_START_ROUTINE)loadLibraryAddress, dllPathAlloc, 0, NULL);
    if(remoteThread == NULL){
        printf("[---] CreateRemoteThread unsuccessful.\n");
        getchar();
        return 1;
    }
    //Start-Address:kernel32.dll!LoadLibraryA

    CloseHandle(hProcess);
    return 0;
}

bad_dll.c

#include <windows.h>
#include <stdio.h>
#include <unistd.h>

BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved){
    FILE * fp;
    fp = fopen ("C:\Users\wsam\Documents\Hacked.txt","w");
    fprintf (fp, "Hacked\n");
    fclose (fp);

    while(1){
        printf("HACKED\n");
        fflush(stdout);
        sleep(1);
    }
}

Answer 1

这是我使用 VirtualAllocEx、CreateRemoteThread 和 LoadLibrary 的 dll 注入器的非常基本的示例：

#include <iostream>
#include <Windows.h>
#include <TlHelp32.h>

DWORD GetPid(char * targetProcess)
{
    HANDLE snap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
    if (snap && snap != INVALID_HANDLE_VALUE)
    {
        PROCESSENTRY32 pe;
        pe.dwSize = sizeof(pe);
        if (Process32First(snap, &pe))
        {
            do
            {
                if (!_stricmp(pe.szExeFile, targetProcess))
                {
                    CloseHandle(snap);
                    return pe.th32ProcessID;
                }
            } while (Process32Next(snap, &pe));
        }
    }
    return 0;
}

int main()
{
    char * dllpath = "C:\Users\me\Desktop\dll.dll";
    char * processToInject = "csgo.exe";
    long pid = 0;
    while (!pid)
    {
        pid = GetPid(processToInject);
        Sleep(10);
    }

    HANDLE hProc = OpenProcess(PROCESS_ALL_ACCESS, 0, pid);
    if (hProc && hProc != INVALID_HANDLE_VALUE)
    {
            void * loc = VirtualAllocEx(hProc, 0, MAX_PATH, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
            WriteProcessMemory(hProc, loc, dllpath, strlen(dllpath) + 1, 0);        
            HANDLE hThread = CreateRemoteThread(hProc, 0, 0, (LPTHREAD_START_ROUTINE)LoadLibraryA, loc, 0, 0);
            CloseHandle(hThread);
    }

    CloseHandle(hProc);
    return 0;
}

此代码包括获取路径字符串的空终止符：

strlen(dllpath) + 1

EDIT: I noticed if I take out all code in the bad_dll.dll while loop it succeeds in creating a thread and doesn't crash the process, why is that?

我相信 DllMain 中的无限循环是导致问题的原因，它永远不会 returns。当您删除循环中的代码时，您的编译器会优化循环并因此停止崩溃。

每个人都说永远不要从 DllMain 调用 CreateThread()，但数百万人都在毫无问题地这样做。问题在于加载程序死锁，但我注入 DLL 已有 5 年，从未遇到过任何问题，这是我的经验，我的信念源于经验。您至少应该通过阅读和访问 this question.

中的链接来了解可能存在的问题

忽略 DLLMain 中的所有 CRT 我建议你这样做：

DWORD __stdcall hackthread(HMODULE hModule)
{
    FILE * fp;
    fp = fopen ("C:\Users\wsam\Documents\Hacked.txt","w");
    fprintf (fp, "Hacked\n");
    fclose (fp);

    while(1){
        printf("HACKED\n");
        fflush(stdout);
        sleep(1);
    }
}

BOOL APIENTRY DllMain(HMODULE hModule, DWORD  ul_reason_for_call, PVOID lpReserved)
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        HANDLE hThread = CreateThread(nullptr, 0, (LPTHREAD_START_ROUTINE)hackthread, hModule, 0, nullptr);
        CloseHandle(hThread);
        break;
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}

以这种方式，CreateThread 和 DllMain return 99.9999% 的时间。

这是根据我的经验得出的概念证明。

进程注入器在 CreateRemoteThread 上崩溃

Process Injector Crashes on CreateRemoteThread

c

windows

process

malware

penetration-testing