Sometimes the biggest threats to your website hide in plain sight.

As a small business owner, it’s important to be aware of the different kinds of cybersecurity threats that exist so that you can take proper measures to protect against them.

Knowing the symptoms of these cyberthreats can also be helpful as it prevents potential cyberthreats from going unnoticed for too long and causing irreparable damage to your company.

Website Backdoors – What Are They?

Among these threats are website backdoors, which are a piece of malware that is injected during initial access to facilitate the next attack. These are called “backdoors” because as the name implies, they leave a door for the attacker to enter through at a later point in time, giving the hacker continuous access to the computer or server they infected.

Website backdoors also aren’t easy to remove– they can stay in a website after running threat scans and updating sites, since they likely already have a higher “authority” within the website, allowing them to stay undetected.

Why Are Website Backdoors Hard to Find?

A website backdoor can be hard to find because it can be disguised as a root application—usually through code within or simply file names. They can also be very small, and I imagine searching for a 2KB file in a 500GB server isn’t going to be easy, or likely for that matter.

However, if you’re a small business owner, chances are you probably don’t have thousands of files that make up your website. In that case, it can be a useful practice for you or your system administrator to know what your files look like, so that you can spot any changes within your server’s files.

Types of Website Backdoors

Believe it or not, there are several types of backdoors that are commonly used, depending on the platform your website runs on: universal backdoors, system-specific backdoors, and complicated backdoors. Let’s start by getting into what universal backdoors are, which are probably the most commonly used type of backdoor to attack websites today.

Universal Backdoors

When it comes to universal backdoors, they certainly aren’t as effective as their complicated counterpart. Usually used by beginner hackers, universal backdoors are often attempted on smaller websites that don’t look so secure, sometimes even spammed on thousands of websites until one falls prey.  

Universal backdoors are usually very short and simple lines of code, which makes them easy to implement on a wide scale, as they are usually written in PHP.

System-Specific Backdoors

System-specific backdoors usually fall in-between universal and complicated backdoors: they can either be very long, or very short. System-specific backdoors have one thing that universal and complicated backdoors don’t: they are specific to one system. This makes them harder to remove, and more likely to be successful.

For example, there was recent news that the WordPress platform was plagued with plugins that had backdoor vulnerabilities within them, and WordPress is used by 75 million people, meaning that even websites you know may be vulnerable.

Complex Backdoors

Like anything complex, complex backdoors take quite a bit of time to make because of their extended features when compared to universal backdoors. Take the Filesman backdoor, for example. It has the ability to “manage files and directories, execute commands, and brute force database passwords among other things.

However, because of how big complex backdoors can be, they are easier to find than other types of malware. This makes protecting against them way easier, as well as web security systems being more likely to find them.

Although they can be powerful, they certainly aren’t sneaky.