What Types of Computer Viruses Should Have You Worried?


December 14, 2021

The Short Answer Is, All of Them. But There’s Cybersecurity Tools to Address All Types of Spyware and Malware. Let’s Take a Look.

Viruses are to computers what viruses are to the human body. These nasty little pieces of code can be a minor annoyance. Some of them can be deadly. But all types of malware and all types of spyware have the potential to do serious damage to your business. What types of computer viruses can affect your bottom line? They all can. And the threat viruses pose to your business is only growing.

What are Computer Viruses, and How Have They Become More Sophisticated?

Put simply, a computer virus is a piece of malicious code that is added to your computer, usually by criminal actors. This code can “infect” your computer, install itself and copy itself to other computers in your network, without the user’s knowledge or permission. Depending on how the virus is written, it can attach itself to your software, data files, backup systems, or even the boot center of your hard drive. Often referred to as “malware,” computer viruses can go anywhere your data goes in your system. And the potential for damage is enormous.

According to the Identity Theft Research Center, 2021 has been a all time record year for the number of data breaches, and the the level of damage they are inflicting is also on the rise. All these breaches are first caused by some kind of computer virus. Let’s talk about the most common types of computer viruses.

Types of Computer Viruses

Viruses can take many shapes and forms. And they can get installed through many different kinds of means. Cyberthieves may try to send emails that look perfectly legitimate, and ask for the receiver to click on links that download malicious code into their systems. Or, they might try brute force attacks, where they repeatedly try to guess passwords until they get into your company’s systems. They may hop a ride when an employee logs onto your system while using a public coffee shop wifi. The methodologies are nearly endless. But the effects are the same. You have code that doesn’t belong running rampant in your system.

Here’s some of the most common types of viruses, and how they behave in your system:

Trojan Horse

As legend goes, during the battle for the city of Troy, the opposing army sent a gift to their enemies that was shaped like a giant wooden horse. But once the gates were lifted and the gift was accepted, enemy soldiers poured out of the sculpture and killed everyone in sight. Fortunately, a Trojan horse virus isn’t likely to kill anyone. But it can lay waste to your data.

A Trojan Horse virus is one that is disguised to look benign. It may come into your network through a phishing or spoofing campaign, and replicate onto every computer in your network. It may hide out in your system under an innocuous file name, so as not to call attention to itself. But once this kind of malware is in your system, it can activate, and do everything from siphoning off customer data to shutting down your network entirely.


Unlike other types of viruses, a worm doesn’t need to attach itself to another piece of code to work. It is a standalone type of malware that reproduces itself over and over to spread throughout your system. It skips from place to place in your network, exploiting known lapses in your security network to keep getting access, and replicating. Think of it as the computer code equivalent of Pac Man, gobbling up and destroying data as it goes.


Spyware is a type of computer virus that is designed to never be detected. Once it’s in your system, it hides, silently collecting data while while your system runs, and transfers sellable data and credentials back and forth. The most effective of spyware can lurk in your system for years, siphoning off data criminals can auction off on the dark web. Or, spyware can be used for corporate or political espionage. It’s one of the most malicious types of computer viruses.


Adware is generally not considered a type of malware or a type of spyware. It’s simply a type of code that attaches to a site so that pop-ups and banner advertising can be displayed. A lot of freeware apps and websites employ adware to make sure they can monetize their sites with advertising, without having to ask for subscriptions from users/visitors. Adware is generally harmless. However, if you get too much of it running on a computer or mobile device, it can slow your download speeds and clog up your systems. It’s generally recommended that you always close down your web browsers and turn off your phone at night, which will generally clear your cache of most adware.

So, now you know most of the major types of computer viruses. What can you do about them? Integris has some resources that can help.

How To Combat All Types of Computer Viruses: Resources to Use Now

There’s a type of cybersecurity tool to defeat or prevent nearly every type of computer virus, from antivirus software, to firewalls, to more sophisticated tracing systems like SIEM or Threat Hunting software. To find out more about the cybersecurity product lineup Iconic offers, check out our latest product brochure. Our blog on the best type of antivirus software and our blog on ransomware basics will also help you get your arms around the issues. Looking to tackle all the types of computer viruses that could be lurking at your business? Download our free, step-by-step guide for creating a cybersecurity plan today!

Susan Gosselin is a Senior Content Writer for Integris. A career communicator and business journalist, she's written extensively on IT topics and trends for IT service providers like Iconic IT and ProCoders Ukraine, as well as business publications such as Technologyadvice.com, Datamation.com, The Lane Report and many others. Connect with her on LinkedIn.

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