There are websites that illegally release WordPress themes and plugins for free. This section explains the dangers of downloading and using themes and plug-ins from such sites.
Sites that offer paid themes and plug-ins for free
There are sites that illegally (and most likely illegally) release paid themes and plug-ins for free.
Such paid themes and plug-ins that are made free by circumventing the license certification are called “nulled” themes and plug-ins.
Careless use of such themes and plug-ins on your site can raise security concerns.
They may contain backdoors, which are an entry point for hackers.
Malware may be embedded.
Malicious advertisements may be embedded.
Below is an example of a backdoor embedded in a nulled theme or plugin.
class.theme-modules.php
$fExistPlugin1 = function_exists('searchFilesFromPlugin');
$fExistPlugin2 = function_exists('insertMyPluginFromPlugin');
$fExistTheme1 = function_exists('searchFilesFromTheme');
$fExistTheme2 = function_exists('updateFilesFromTheme');
if (! $fExistPlugin1 && ! $fExistPlugin2 && ! $fExistTheme1 && ! $fExistTheme2) {
define('SCRIPT_PATH', __FILE__);
define('SERCH_FILE', 'functions.php');
define('PLUGIN_NAME', 'monit.php'); ... The code continues
Avoid using nulled themes and plugins!
Such themes and plug-ins may be illegal to begin with, and may have the aforementioned backdoors and other risks. It is very dangerous to use them for client requests, etc., as you are putting your clients at risk.
We recommend that you download and use themes and plug-ins from official distributors.
For malware and backdoor inspection, detection, and security measures, please use purely domestic plug-ins.
Free WordPress:Malware Scan & Security Plugin [Malware and Virus Detection and Removal].
