ITPubDownloader.user.js

// ==UserScript==
// @name                ITPub downloader
// @author              TheCjw
// @description         test
// @namespace           http://github.com/thecjw
// @updateURL
// @downloadURL
// @include             http://www.itpub.net/*
// @version             1.03
// @require             http://libs.useso.com/js/jquery/2.1.1/jquery.min.js
// ==/UserScript==

(function() {
  'use strict';
  $(document).ready(function() {
    $('ignore_js_op').find('a').click(function() {
      var downloadLink = $(this).attr('href');
      var re = /(?:attachment\.php\?aid\=)(\w{58})/i;
      var result = re.exec(downloadLink);
      if (result !== null) {
        var fileId = result[1];
        var url = "http://www.itpub.net/" + 'forum.php?mod=attachment&aid=' + fileId;
        console.log(url);
        window.open(url);
        return false;
      }
    });
  });
})();