I'm Afraid I'll Get a Virus

Unlike a virus that a human or animal catches, which was created by Mother Nature, a computer virus is a program, written by a human being, to do bad things to your computer. (Or, at the very least, open up a "hole" in your Internet connection through which advertisers can send annoying pop-up ads).

These programs are called viruses (or worms) only because they behave like viruses found in nature. When you (as a human) get a virus, you get sick because the virus replicates itself (makes copies of itself) and starts spreading throughout your body. A computer virus is much the same. It's a program that's able to make copies of itself, and spread itself throughout files in your computer.

Most viruses can also spread themselves by e-mailing themselves to people in your address book. You won't be aware that you're sending out these viruses, even if you're sitting at your computer while it's happening. Your friends will just start receiving e-mails from you with the virus attached. Likewise, when a friend of yours receives a file, it's likely that the virus will e-mail itself from their computer to yours.

As a rule, a virus will be sent as an attachment to an e-mail message. In some cases, the return address on the e-mail message will be your friend's e-mail address. In other cases, it will be some other bogus return e-mail message. For example, Figure 1 below shows my e-mail Inbox. I can tell, without even opening these e-mails, that the e-mails are not really from support@microsoft.com, and that all the attachments are all viruses.

Figure 1

All the messages with support@microsoft.com are suspicious to me for several reasons. For one, I haven't written to support@microsoft.com lately, so I'm not expecting any e-mail from them. For another, the body of the message doesn't really tell me what's in the attached file. When a virus sends itself to another computer, it tends to put only a tiny amount of text, or no text at all, into the body of the e-mail message. Another reason I'd be suspicious of the attachments in Figure 1 is that I know that Microsoft wouldn't send me (or anyone else) an attachment. It's just bad policy to be sending out e-mail messages (with or without attachments) to people at random.

If I were to open one of the attachments from Figure 1, my computer would then be infected with the virus. (I don't have to worry about this though because my e-Mail client, Microsoft Outlook, won't allow me to open any of these). Once my computer is infected, the virus would try to send copies of itself out to other people in my address book. (It would fail there too, though, because Outlook would warn me when a virus is trying to send itself).

Anyway, the question becomes "How does the average person tell the difference between a legitimate e-mail attachment, and a virus, just by looking?" You really can't. But there are steps you can take to protect yourself from viruses. For starters, never open an e-mail attachment unless:

1. You know who it's from
2. You were expecting the attachment
3. You know what's in the attachment

Remember, a friend's computer can send you a virus without your friend even knowing it. So don't assume that just because it's from a friend, it's safe. If in doubt, write your friend and find out if they sent you an e-mail with a legitimate attachment. Also, there's no guarantee that the return address on the e-mail is the real return address. So don't rely entirely on the sender's e-mail address as a means of determining whether or not an e-mail attachment is a virus.

E-mail messages aren't the only way viruses are spread. Many programs that you can download for free will be infected as well. Any time you get an e-mail message offering some cool, cute, free program you can download just by "clicking", be suspicious. Be very suspicious. In particular, be very leery of "cute". In the computer world, "cute" most definitely doesn't equate to "harmless".

Be aware, though, that not all downloads are dangerous. Downloads from legitimate software companies like Microsoft or online services like www.tucows.com should be perfectly safe.

Finally, you should purchase, install, and learn to use anti-virus software. If your computer came with anti-virus software, then you just have to learn to use it. You should be able to find some instructions in with the rest of the printed material that came with your computer.