Computer Worm & Virus: A Definition and Important Information To Understand

It seems these days you can't go more than a week or two at most without hearing about a new worm or virus spreading on the internet. While you probably have a general idea what they are, you may wonder where they come from and what the difference between a virus and a worm is.

Both viruses and worms are very similar, for the most part. They are malicious pieces of software which cause a variety of problems for computer users including: causing your computer to constantly restart so it's impossible to use, emailing your personal documents to strangers, erasing your documents or your entire hard drive, or even using your computer to send spam.

The main difference between a virus and a worm is that a virus requires a person to run it for it to cause problems, while a worm spreads and causes damage without human intervention. So in other words, for your computer to be infected by a virus, you generally need to do something, like open and run an attachment to an email, while with worms your computer can be infected even if you don't do a thing.

Many viruses and worms take advantage of the frequent security holes discovered in many Microsoft programs and operating systems (Windows). Microsoft regularly releases patches to fix these holes, but many users don't know about them or don't know how to apply the patches, which leaves them vulnerable, and the patches can take weeks or months to come out.

For example, in 2003 a group of people discovered a vulnerability in Windows which worked as follows: one computer would send a special request to a second computer over and over and over, thousands of times in a second. Now the second computer was supposed to ignore those requests because they weren't coming from an authorized computer.

However, due to a bug (or programming error) in some versions of Windows, if enough requests happened fast enough, the second computer would essentially throw its hands up in the air and say "whatever you say next, I'll do!" and whatever instruction that computer was given next, it did it.

So all someone had to do was write a worm which would make those thousands of requests, the vulnerable computer would say "tell me what to do" and the worm would say "install me," and the infected computer would go on and do it to the next computer, which would do it to the next one, over and over and over, causing the worm to cascade accross the world, infecting thousands of computers in minutes.

Microsoft, recognizing the problem, created a software "patch" which sealed the security hole. A month after the patch was released, someone created and released the MSBlaster worm. Because millions of Windows users hadn't installed the patch, their computers got infected, and suddenly they found they couldn't use their PCs for more than five minutes without the machine restarting.

People who used Macintosh computers, and other computers not running Windows had a natural immunity to this and most other worms and viruses. There are well over 100,000 known viruses and worms for Windows, and fewer than 70 (yes, only seventy) for Macintosh, by comparison. In fact, those Mac viruses only affect very old Macs, and there is just one virus that runs on current Macintosh computers (ones running OS X) and that virus isn't considered a real threat because of the built-in security of OS X.

If you run Windows, as you must realize by now, it is absolutely essential for you to keep your computer patched with the latest security patches as soon as they come out -- although to be fair, Macintosh users should also install any security patches for their OS, for just because there aren't any viruses for OS X, it doesn't mean it's impossible for one to be written!

Beyond that, it is an incredibly bad idea to run a computer without having current, up-to-date antivirus program such as Norton Antivirus installed and running on the computer. When I say current and up-to-date, I mean that there is essentially a list of viruses that gets updated as often as every day. If your computer's antivirus software doesn't have the current list, it can't protect you against viruses and worms. So if you have a three year old copy of McAffee antivirus, you are not safe.

Even if you have a 1 month out of date copy, you're still not safe!

Then there's the question of whether you're even using the right antivirus program in the first place! In 2006, tests revealed that the top three most popular antivirus programs -- Norton, McAfee, and Trend Micro, had a staggering 80% failure rate at detecting the latest threats!

It seems that the virus and worm writers are using those three programs to check to see if the programs find the new virus. If the programs detect it, the virus writer keeps working on the virus until it gets through undetected. And then he releases it "into the wild," where it infects all the PCs using those three programs.

The best option right now seems to be a program called Kaspersky, which consistently ranks as the best antivirus program to use, with a success rate of 99.6% at protecting your computer!

Protecting your computer from viruses, worms, and the many other threats can seem complicated and time consuming to a lot of people. But don't make the mistake of ignoring the problem; protect yourself, or you could end up regretting it.

If you need a little help, take a look at my Safe and Easy Web & Email CDs that come as part of the bundle of CDs I have for Windows computers. They lay it all out, step by step, so you can easily protect yourself and avoid problems.