How Did I Get A Virus On My Computer?

I spent years fixing computers, and the number-one question I always heard after a particularly nasty viral infection was, "How did the virus even get in there?" For the sake of propriety, we could never actually get too specific, but since I don't work for a computer store anymore, I no longer have such qualms. Here's how your computer got infected.

You did something.

Some people take it as a given that they will get a virus at some point, and when it happens they throw their hands in the air and say, "That's computers for ya! They have a mind of their own!"

No, they don't. You did something to get the virus into your computer.

Well, what did I do?

There are a few major places where they come in. Maybe you found a website that lets you download music for free, and a virus hitched along for the ride. Maybe someone went to a sketchy porn site. Maybe one of your kids played some "free" game that did it. Maybe someone downloaded a toolbar onto the computer. The point is, you did something.

But no one in my house did anything like that!

Yes they did.

No they didn't!

Yes, someone did.

But I know my family! They certainly wouldn't-

Look, look. We can go around on this for a while, but the truth is the truth. Someone did something. Viruses just don't happen.

Heck, it could have even been an accident! For example, a while ago my wife saw something about coupons online. She clicked on it, and it downloaded some weird coupon toolbar that was a pain to get rid of. These things happen, but the point is, someone did something.

But I have an antivirus program!

All right, is it a recent program?

I don't know!

Is it updated?

I'm not sure.

Who makes it?

I couldn't tell you! Why does it matter?

Just having an antivirus program isn't enough. There are always new viruses coming out, and if your computer doesn't have a recent program or isn't properly updated, you're in trouble.

Well, what's a good one?

There a few free ones I recommend: Avast and Microsoft Security Essentials. There are other antivirus programs that cost money, but if you're responsible you shouldn't have a problem.

Responsible? What do you mean?

Some people make the mistake of looking at an antivirus program as a "get out of jail free" card. They think, "I have an antivirus program! Nothing bad can ever happen to my computer ever!" It's not really like that.

Think of an antivirus program as your immune system. It does a lot of stuff in the background that you don't really notice, and it's fairly reliable. However, if you go rolling around in a vat of rusty plague needles, your immune system can't help you.

In the same way, your antivirus program is there to help you against normal, everyday stuff. But if you engage in risky behaviors, you'll get an infection.

But I went to this sketchy site one time and nothing happened!

Congratulations! One time I fell out of a tree and didn't break any bones! That doesn't mean I'm going to climb the tree and fall out of it again, though.

But-

Dude, NO.

The worst offenders are those people who do something risky, get a warning from their antivirus program, then proceed to turn their antivirus program off and do the risky thing anyway just because "they wanted to go to that site." Seriously, what is wrong with you people?

I get it, fine, I'll be more careful. Anything else I can do to stop infections?

Run Windows Update.

But one time Windows Update totally destroyed my computer! And this one time, a friend of mine said that they ran Windows Update, and then their cat died!

Windows Update by itself isn't going to ruin anything. Maybe one out of every thousand updates is going to have some minor problem that Microsoft rolls back immediately, certainly not enough to justify turning it off.

Aside from Windows Update, run other updates on your computer. If something like Adobe Reader, Adobe Flash Player or Java asks you to update, update it. For the love of God, please update it.

Why?

Because people are constantly trying to break into those programs. The manufacturers see a flaw that can be exploited, and then fix the flaw. If you're not updating the program, the flaws remain. So, just update the dang programs, all right?

Anything else I should keep in mind?

Yes. If someone fixes your computer and cleans off the infections, any recurring infection is not their fault. I want to make that clear. People have been conditioned to think of viruses as normal, every day wear and tear on their computer, and that perception needs to change.

Basically, it's the difference between getting your car's oil changed and getting into a car accident. The oil on your car needs to get changed regularly, and it's a part of scheduled maintenance. If your car's oil is changed and then it starts dripping oil, you could rightfully go back to the garage and complain.

However, if you get into a car accident, take the car to the garage and get it fixed, then get into another car accident, it's not the garage's fault. If you keep getting into car accidents, maybe you should be a better driver.

Similarly, stuff like updates is part of the regular maintenance of your computer. Viruses are not. If you keep getting viruses on your computer, take a hard look at what you're doing online and see if you can't figure out where you're going wrong.