What’s a virus and how does my computer catch one?

Last week we talked about common computer parts and saw a high-level description of their basic purposes.

This week we’ll start talking about common software. The logical starting point would be the operating system, but I’ve decided to start with antivirus software because I want to encourage everyone to run some sort of antivirus software on their computers. (We’ll talk about operating systems another day.)

What’s a computer virus?

A computer virus is a type of malicious software (malware), but the term “virus” is often used to refer to all malware. Malware is software put on a computer system on the sneak, without the user knowing about it. It may have evil purposes, like messing up your files or grabbing financial information. Or it might just be annoying, like popping up a particular website every time you log in.

Using last week’s metaphor of your computer being represented by your house (with bookshelves representing your hard drive and a bulletin board representing memory), a virus is like a sick kid that sneaks into your house, then tears notes off your bulletin board, puts his own notes up, messes with your bookshelves, wipes snot all over your kids to infect them, and even hides a voice recorder on your bookshelf to spy on you.

How does my computer get a virus?

Nobody in their right mind would want one, so viruses have to sneak onto your computer when you least expect it, like:

• when you download a program from the internet. My sister’s computer once got infected after she download a free screensaver.
• when you get on some websites. Google can be your friend, but be vewy vewy careful before visiting a link.
• when you open an infected email. Junk email can sometimes be dangerous.
• when you get on a public network (for example, at a coffee shop).

How do I protect my computer from viruses?

An ounce of prevention truly is worth a pound of cure. The best thing to do is to change your behavior to minimize your chances of getting a computer virus. Some things you can do (or not do):

• Download software only from reputable sources. I almost always go to CNET first if I want to download something in particular or look for free software. Notice in the image below (which is part of the screen that you’ll see when you try to download something from the CNET website) that the download has been tested as spyware (malware) free.
  
• Don’t click on links in emails unless you’re sure that they’re safe. As a matter of fact, don’t even open the email if it looks suspicious at all. Even if the email is from your best friend or Aunt Sally. Just say no.

Common sense will save you a lot of grief. Not using common sense is like sending your kid down the street to play with the kid with the flu. Your kid is more than likely gonna get sick and you’ll kick yourself while giving your child Tylenol in the middle of the night and wonder what you were thinking.

Along with common sense behavior, we should all have some sort of antivirus software on our computers. A good free one for Windows users is AVG. Mac users can try iAntivirus (also free). You can pay good money for antivirus software, but it will most likely come with features or tools that you will never use, and may even be more harmful than helpful. I personally had a bad experience with a Norton antivirus program that slowed my system down to the point of being unusable. And I paid for the privilege. (I’m still irritated when I think about that, so don’t even get me started.)

Have you ever had a close encounter with a computer virus? Do you know how it got on your system?