Virus Guide

It seems like each and every day I get an e-mail or two about the latest and most deadly virus to date. Since there are thousands of viruses out there, it would be impossible to watch out for all of them. So, I'm going to give you some general virus guidelines that you can use to help keep yourself from getting infected. It's like that old saying, "Type code for a man and get his program running for a day. Teach him C++ and get his programs working for life".

Ok, maybe that's not the *exact* way that one goes, but you get the idea.

What is a virus anyway?

A virus is an unwanted program that, in almost all cases, the user accidentally installs onto his or her computer. Some are relatively harmless and cause little, if any, damage. Some are much more hazardous and can render the information on your computer's hard drive useless. Most just like to try to share your information, crash your computer, and spread themselves around.

So why do people make viruses?

Well, some (maybe most) do it just to see if they *can* do it. Some are genuinely looking to cause havoc. Others, and these are the ones to watch, are trying to get personal information from you. Many of the viruses out there are used to send their creator information from your computer via e-mail. Sure, there are more than just those 3 reasons, but I believe those to be the primary ones.

A day in the life of a virus

Since most of the viruses that give people trouble tend to be in the form of e-mail viruses, I'm going to give you the low down on how most of these puppies work with our computer buddy, "Jim".

Let's say Jim goes to work and checks his e-mail like he always does. He notices an e-mail from someone he knows with an attachment. The e-mail says something generic like "Hey, check out this attachment, it's really cool".

In all likelihood, there will be no signature (although there could be).

So, old Jim clicks the little paperclip icon and runs the attachment. It probably ends in ".exe" or ".zip".

Maybe he gets a cute little display on his screen (the Happy99 virus gave the user a fireworks display). Jim thinks "Hmm, that was cool" and gets back to work, completely unaware that he has been infected.

Now the virus goes to work. The first thing it will probably do is get into his address book and send itself to everyone in it. When these people get the e-mail virus, it looks like their friend Jim has just sent them a cool little file to check out. Old Jim doesn't have a clue that this has even transpired but now all his friends are opening up this little file and infecting their own computers (and sending it out to everyone in their address books). Do you see how these things can infect millions of computers in a hurry?

Another route the virus can take is to send a second e-mail with itself attached to anyone you are sending a message to. For instance, say you send Jim a message. Jim checks his e-mail and sees your message plus another message from the virus that you didn't even know you sent.

A quick way to check and see if you are infected with this type of "piggy back" virus is to send yourself an e-mail. If you get a second e-mail with an attachment, you're infected (note - this only works for viruses that spread themselves as described above).

Another way these e-mail themselves is by choosing an address from your address book as the "from" person (The Klez virus does this). So, it looks like one of Jim's friends is sending out viruses form their computer, but it's really coming from his machine.

Jim's friend then gets lots of e-mail from people telling him that he's sending out viruses! Of course, he's not, but Jim is. (In addition, Jim may get an earful from this (now former) friend once he figures out what happened!)

OK, I now what you may be thinking. Maybe you have 500 people in your address book and it seems like you would notice that there was an excessive amount of e-mail going out when you send / receive.

Well, you may with some viruses, but the smarter ones have an "SMTP" engine built in. Simply put, they can send e-mail from your computer without using your e-mail software or server. This is done is the background and may seem like nothing more than a sluggish internet connection.

Sneaky, aren't they? That's how most e-mail viruses work.

Posted in: Virus Guide