9 Common Types of Computer Viruses

Most people know how to prepare for cold and flu season: wash your hands, cover your mouth when you cough, cover your nose when you sneeze, get plenty of rest, and avoid people who might be sick. It’s something we learn from a young age.

We know to take these precautions, because we know how humans contract viruses. In the same vein, when you understand how viruses infect computers, you can take better preventative measures to prevent viruses and identify a virus before it rages out of control.

Here, we illustrate how you can recognize nine common computer viruses.

• Ransomware Attacks and Data Recovery. In a survey of 5,400 IT decision-makers, Sophos found that “on average, ransom-payers got back just 65% of the encrypted data, leaving more than a third inaccessible, while 29% said they got only half of the data back.” Learn more about ransomware.
• Costs of Cyberattacks. According to IBM, the average cost of a data breach in the United States is $3.86 million. It takes 280 days on average to identify and contain a breach.
• Repeat Computer Viruses. In a survey of 1,300 security professionals, Cybereason found that 4 in 5 businesses that chose to pay ransoms suffered a second ransomware attack.
• Computer Virus-Related Identity Theft. In 2020, the FTC received about 1.4 million reports of identity theft, double the number from 2019.

1. Resident Virus

Resident viruses set up shop in your RAM and meddle with your system operations. They’re so sneaky that they can even attach themselves to your anti-virus software files.

2. Multipartite Virus

This virus infects the entire system – multipartite viruses spread by performing unauthorized actions on your operating system, folders, and programs.

3. Direct Action

This virus targets a specific file type, most commonly executable files (.exe), by replicating and infecting files. Due to its targeted nature, this virus type is one of the easier ones to detect and remove.

4. Browser Hijacker

Easily detected, this virus type infects your browser and redirects you to malicious websites.

5. Overwrite Virus

As the name implies, overwrite viruses overwrite file content to infect entire folders, files, and programs.

6. Web Scripting Virus

This sneaky virus disguises itself in the coding of links, ads, images, videos, and site code. It can infect systems when users download malicious files or visit malicious websites.

7. File Infector

By targeting executable files (.exe), file infector viruses slow down programs and damage system files when a user runs them.

8. Network Virus

Network viruses travel through network connections and replicate themselves through shared resources.

9. Boot Sector Virus

One of the easier viruses to avoid, this virus hides out in a file on a USB drive or email attachment. When activated, it can infect the system’s master boot record to damage the system.

The key to protecting yourself from computer viruses is having multiple layers of cybersecurity defense. Having a firewall or anti-virus is a great start, but it isn’t a comprehensive solution. There are multiple layers to consider in a cybersecurity plan, like user education, endpoint detection and response (EDR), DNS filtering, and more. Learn more about the 11 layers of cybersecurity.

Your individual solution will depend on factors like the size of your business, industry, organization type, and long-term business goals. The easiest way to illustrate multilayered computer virus protection, is by imagining each individual layer of cybersecurity as a slice of swiss cheese. Each slice has a few holes in it, and as you stack slices on top of one another, you cover up the holes. Download the Essential Business Guide to Cybersecurity.

Have you been noticing symptoms of a computer virus lately? Are you looking to reevaluate your current cybersecurity solution? We can help.