How Do Computers Get Viruses?

Computer viruses and other malware are designed to spread. They jump from computer to computer, using network connections to infiltrate a computer's files and install software that steals your money and personal information.

To many, the spread of computer viruses seems like a mystery. If you've ever asked yourself, "How do computers get viruses?" you'll find your answers below.

Most Malware Is Installed by Users

Most computers have security patches installed to prevent viruses from downloading themselves onto a computer without the user's permission. However, fake antivirus software has a way of tricking people into installing it by making them think it's a friendly program. Here are some of the ways you might accidentally install a virus:

  • Via Download
    Computer viruses are often present in download packages for seemingly legitimate software or files. You can perform a virus scan on all downloads using antivirus software. Be especially careful if you are downloading insecure files uploaded by a user, such as pirated video and music files. For the most part, you should avoid downloading files like this entirely.
  • Via Email
    Spam email is a common way for a virus to spread, as these emails may contain attachments or links. Never open an attachment or a link from an unfamiliar email. If you have to download anything from an email, make sure your email provider or antivirus software scans the attachment for viruses.

Don't make the mistake of trusting an email just because it seems to be from someone you know. Your friend may already have the virus, which is then spreading itself via email without them knowing. As a general rule, if an email looks at all suspect, don't click any links or open any attachments!

  • Via Bad Links
    Bad links appear on all kinds of websites and in online advertisements. They might disguise themselves as something you're looking for, such as a needed webpage or download. A bad link might tell you it is going to download Adobe Flash on your computer, but it might just download a virus instead. To keep your computer safe, always download necessary files directly from the official provider or on an official download site.

To avoid bad links, never click on links appearing in pop-ups or other advertisements. If you accidentally click on one, just make sure you cancel any download prompts that appear. Antivirus software will protect you from any virus downloads you may have initiated.

Other Malware Sneaks In

Your computer can still become infected with a virus without you ever clicking on a bad link or initiating an installation. This is a rare occurrence, especially if you keep your operating system up to date by installing updates regularly, but it does happen. A virus built into a website can install itself in the background while you browse the internet. As long as you are connected to a network, you are always vulnerable to a virus.

The best way to protect yourself from computer viruses is by being careful. Avoid suspicious links and downloads, keep your computer's OS up to date, and install only trusted antivirus software.