What is a Website Backdoor? 4 Ways to Prevent the Hack

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Have you ever wondered about your website backdoor? Or did you know your website even had doors?

Try to imagine for a moment that twelve months from now, your website has become so successful that your profits have doubled and you’re finally getting some positive traction in your business. Then, in a moment, all of that momentum comes to a screeching halt when a hacker installs a website backdoor on your site.

If you’re not familiar with website backdoors and how to avoid or remove them, you may end up spending thousands of dollars and countless hours trying to repair the damage done by this type of hack. And that doesn’t even account for the revenue you’ll lose while your website is out of commission.

The fact is that no website owner wants to live in constant fear of a malicious hack on their site. Because of this, many site owners spend hundreds of dollars every month trying to avoid backdoor attacks or solve the ones that impact their site. But there has to be a more effective way to deal with this problem. Let’s take a look.

In this guide

What Is a Website Backdoor?

In a nutshell, a website backdoor is a hidden entry point that offers unrestricted, unauthorized access to your website to anybody who has knowledge of it.

It can be very difficult to manually detect if your site is infected with a backdoor entry point. The simplest way to know if your site has a backdoor is if it continually gets hacked even after you thoroughly clean it after each hacking event.

A backdoor is hard to manually detect because they appear on your site in the same way that other malicious codes do, such as the favicon.ico virus. But backdoors are unique. They can be extremely sneaky and hidden very well within the code of your site.

In fact, manually finding backdoor code can be a lot like searching for a unique piece of hay that’s buried in a barn full of identical-looking hay.

Some website backdoor code is designed so deceptively that it can easily be confused with regular, non-malicious code on your site. Beyond that, the backdoor code can be hidden in many different areas of your site’s code.

You can almost think of an undetected website backdoor as a disease that hasn’t yet been discovered. When a doctor doesn’t know the exact disease they’re looking for, and you have fallen ill to it, you’ll end up suffering without proper treatment. 

The same principle applies to website backdoors:

A backdoor infection that hasn’t been discovered will make your website highly vulnerable to continued hacks. It makes your website vulnerable and, if left “untreated,” has the ability to completely take down your site.

How a Website Backdoor Infection Impacts Your Website

A website backdoor infection has the potential of causing extreme damage to your website. If your site becomes infected with a backdoor, you’ll likely face the following severe consequences:

  • Loss of site traffic due to your users being redirected to unauthorized and malicious websites
  • Unknown and unauthorized popups start to appear on your web pages that ask your users to click and download mysterious software onto their devices
  • Users of your site begin to receive a bunch of spam emails
  • You notice large files saved on your server that you didn’t authorize, such as pirated TV shows and movies
  • Hackers begin to steal medical records or credit card information from your site and sell the information to other Internet users on the dark web
  • Your advertising space has been hijacked and the hacker is now displaying their own ads in the place of yours, thus profiting from your site traffic and clicks
  • Your site’s SEO ranking drops due to a slower site response time, unauthorized traffic redirects, and spammy keywords injected into your site that search engines don’t like
  • Your site may end up on the Google blacklist, as well as losing your Google Adwords account. Your host may even suspend your account when they find out it’s been hacked by a website backdoor.

Of course, you don’t want any of these consequences landing on you or your business. So you’ll need to remove the backdoor from your website before any more damage is done.

To prevent any of these from happening, you need to remove the backdoor from your site.

What is a Website Backdoor

What Are Common Backdoors?

Backdoors are categorized into:

  • Simple backdoors
  • Complex backdoors
  • CMS Specific backdoors

Simple backdoors are one-liner shortcodes that appear to be innocent and are extremely difficult to manually identify.

Complex backdoors are multi-liner codes that a trained eye may be able to easily find. These kinds of backdoors have complicated functions that make them easy to distinguish from simple backdoors. Often a hacker will obfuscate complex backdoor code to make it difficult for malware scanners to detect.

In a CMS-specific backdoor, a hacker will tailor coding to be specific to a CMS (content management system). These are built-in backdoors that are specific only to a single CMS, such as WordPress. They won’t be found on other platforms like Drupal or Joomla.

How To Remove a Website Backdoor

To manually remove a website backdoor, you’ll need to thoroughly analyze your site’s code. In most cases of backdoor infections, you’ll find the malicious code hidden within a PHP file on your server.

For example, if you’re using WordPress as your content management system, the code can be inserted into:

In some cases, they can even be standalone files. Backdoor codes can be located in any directory that is accessible to the public. This makes them easy for the hacker to access when they want to put them to use.

When you locate a backdoor and want to remove it, the first thing to do is create a full backup of your database and site files. This is best done with a WordPress backup plugin like BackupBuddy.

Then, you’ll want to review the raw HTTP access log files. This is because backdoor use is normally performed by using a POST HTTP request to a specific file.

If you have a WordPress administrative account that’s compromised, it will allow a hacker to use your site’s core theme editor to add a website backdoor to your theme’s 404 files. By doing this, every single request to your website that results in a 404 error will serve up a backdoor that anyone can use (as long as they know the backdoor exists).

To remove a backdoor, you’ll need to find the specific thread of code that gives hackers unauthorized access to your site, then completely remove that code. Doing this will require a solid understanding of the code that powers your WordPress site.

By using a WordPress security plugin such as iThemes Security Pro, you’ll know your site is being monitored for themes and plugins with known vulnerabilities and that these vulnerabilities will be automatically updated. This helps solve the problem of backdoors that are caused by plugins and themes.

How to Prevent Website Backdoor Hacks

A backdoor can only be placed in your WordPress site if a hacker has direct access to the site. In order to protect and secure your website from a potential backdoor infection, you’ll need to:

  • Fully secure and lockdown your site from bots and hackers by using the WordPress security plugin iThemes Security Pro
  • If a hacker or bot is somehow able to breach the first line of defense and gain unauthorized access to your site, you’ll need to make sure they aren’t able to insert a backdoor

This can be done by following a few simple instructions.

Put a Firewall To Use

A firewall is able to put a barrier between your site and your site traffic, by device or country. Every user who attempts to gain access to your website first gets investigated by the firewall you’ve employed.

The firewall works to identify if a user’s IP address has been previously flagged for malicious activity. In cases where it has been, the user will immediately be blocked from site access.

Using a firewall is one of the preferred ways to block hackers before they’re able to gain unauthorized site access.

Keep Your Site Updated At All Times

Just like any other types of software you use, WordPress core, themes, and plugins all develop vulnerabilities over time. And when a core, theme, or plugin developer discovers new potential security vulnerabilities, they quickly work to release a repair patch through an update.

If you delay running these updates or fail to run them all together, your WordPress site is now vulnerable to a new hack. And hackers are experts at finding these weaknesses and exploiting them before they’re resolved.

By simply keeping the software you run on your WordPress site completely updated, you help ensure that your site remains secure. Here’s more info on how to update WordPress.

Get the weekly WordPress Vulnerability Report

Always Avoid Nulled Themes and Plugins

A pirated theme of a plugin is a premium product that you download and use without paying for a license. While it may sound tempting to use premium themes and plugins for free, they come at a huge cost.

Nearly all pirated software is infected with website backdoors. When you install these products on your site, you immediately enable hackers to access your site without your knowledge or authorization.

And that is the motive for almost every publisher who puts pirated WordPress products on the market for download.

It’s crucial to never use any pirated themes or plugins on your site. If you currently have one (or more) installed, make sure to immediately delete it from your site. Then, use iThemes Security Pro to scan your entire site to make sure you aren’t running any other themes or plugins that are littered with malicious code.

Keep Your Login Page Protected

Afte themes and plugins, your login page is the next most vulnerable point of your site. In fact, it’s the most vulnerable page on your entire website.

Through brute force attacks, bots will try hundreds, or thousands, of different login credentials within a few minutes to try to gain unauthorized access to your site. And they’ll keep trying until the correct login credentials are found.

Several different measures can be employed that can protect your login page from bots and hackers. The forced use of strong passwords is one measure that will keep brute force attacks from succeeding.

The use of reCAPTCHA is another protection you should use.

When you use iThemes Security Pro, you’ll be able to easily force strong password use on your site, as well as add in CAPTCHA as an added security measure. Beyond that, you can require two-factor authentication (2FA) for users. This will ensure that brute force attacks will never be able to succeed.

Preventing a Backdoor Infection

Even if you take all of the suggested measures to protect your site from a backdoor infection, you still could be hacked.

For example, if you’re using a WordPress security plugin that hasn’t released a patch to repair or report a new known vulnerability, your site could get hacked prior to the update arriving.

If this happens, it’s better to be prepared than to be caught off guard.

To keep a hacker from putting a backdoor on your site:

Harden Your Site

A hacker will disguise their backdoors to make it difficult for a website owner to find them. They are often put onto a site by using a rogue theme or plugin. If your site is already using a lot of themes or plugins, it’s easy for a hacker to secretly install a new plugin that’s infected with a backdoor. After all, you may not even notice.

To keep this from happening, you can completely prevent any installation of themes or plugins on your site. Then, if you should later decide to install a new theme or plugin on your site, you can temporarily enable theme and plugin installation, then turn it back off when you’re done.

The problem is that hackers are also able to insert backdoors into your existing themes and plugins. In fact, anyone who has access to your WordPress admin account can do this. All they’d need to do is navigate to Appearance >> Theme Editor, and insert the malicious backdoor code.

To keep this from happening, you’ll need to harden your site to the point of disabling your file editor.

Use Least Privileged User Access

Hackers have a couple of different ways to implant backdoors onto your WordPress site. One of the ways is to edit the theme or plugin editor. And in order to have access to the editor, they need to have admin-level site access.

Because of this, it’s incredibly important to be selective about the people to whom you give admin site access.

WordPress will allow you to choose between six different user roles for each of your users. The roles are:

  • Subscriber
  • Author
  • Contributor
  • Editor
  • Admin
  • Superadmin (applies only to multisite accounts)

Before giving anyone site access, make sure you consider the role they should be allotted. Standard site users should be allotted roles that don’t have a lot of capabilities, such as Subscriber or Author.

Restrict site admin roles to only two or three people at the most. 

Use Developers You Trust

If you need to hire a developer to build something custom for your site, they’ll need full admin access to complete the task. This means that you should only work with developers that you trust.

Some of the most trusted sources for hiring a WordPress developer include:

  • Stack Overflow
  • WordPress Jobs
  • Codeable.io
  • Smashing Jobs
  • WPMU Dev Pros

You can rest assured that developers you hire from these sources won’t install any backdoor code on your site.

Protecting Against Website Backdoors

The best step you can take right now to avoid the damage done by a backdoor hack is to download and install the iThemes Security Pro plugin for WordPress.

iThemes Security Pro will scan your site for malicious activity 24/7 while enabling you to employ the site hardening measures needed to avoid backdoors. And if your site is ever hacked, the plugin will walk you through the best ways to clean it up before any more damage can be done.

Keep your WordPress site safe from hacks and malicious attacks by using the iThemes Security Pro plugin. Your future self will thank you.

What is a Website Backdoor

Posted by News Monkey