SHCC WYSIWYG Article from October 2003

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This article appeared in the October 2003 WYSIWYG newsletter.

Computer Worms and Viruses

by Jerry Carson

Q: Dear Ask The Expert,

With all the trouble that's been going around, what's the difference between a computer worm and a virus and how do I protect myself?


A: Dear Worried,

First I'll answer the technical part of your question.  A worm is a computer program that is designed to break into a computer using a network connection.  This can be a local network or the internet.  Worms usually take advantage of poorly written operating systems or drivers or poorly configured internet programs.  Once a worm has infected a computer, it then uses that computer to try and infect others.  Often the worm will not damage the host computer until some trigger event occurs.  This could be a certain date or a command via the network.  Worms can spread very rapidly and can often be triggered to perform a number of actions including attacking various companies (Microsoft was the target of the most recent worm attack.

Viruses, on the other hand, cannot spread from computer to computer on their own. They need some human action to activate them.  This action could be running an e-mail attachment, running a downloaded program, or inserting an infected diskette.  Once the virus has been activated it will try to spread. This can be done by infecting other programs, e-mailing itself to others, or writing itself to other diskettes.  After attempting to spread the virus may or may not harm the host computer.

One very annoying type of "virus" is the Hoax email virus.  This is not really a virus at all!  It is simply an e-mail warning about a very dangerous virus and asking the reader to forward the warning to all their friends.  The reader often does this without ever checking to see if the virus is real or not.  As more and more people do this, a large amount extra network traffic is generated which is often more annoying than a "real" virus would have been.

Now for the rest of your question.  What can you do about these threats?

1) Get an anti-virus program.  Get one today!  Make sure it comes with a subscription to keep it up to date with the latest viruses and update it often.  I use AVG from GriSoft.  It is free and has an automatic update feature.  It can be downloaded from

2) Make backups often.  Even the best anti-virus programs are not 100% effective.  Make sure if a virus or worm does hit, that you are prepared. Afterward is too late!

3) Keep you operating system up to date.  For Microsoft users that means going to and installing the patches.  Do this on a regular basis.  I do this about once a week.  Microsoft actually had a patch for the MSBlast worm 4 weeks before the worm was released.  People who updated their operating system during that time did not get the worm.

4) Be very careful about opening e-mail attachments.  This is by far the most common way that viruses are transmitted.  NEVER open an attachment from someone you don't know!  Even if you know the sender make sure you are expected the attachment.  Many virus use the e-mail of the infected system, so your friend may be sending a virus without knowing it.  Also, companies like Microsoft or Norton never send out patches by email.  If you get a patch fromthem via e-mail, it's a virus!

5) Make sure a virus is real before you tell everyone about it.  There is no need to panic your friends and family because someone sent you a hoax.  I use to check on the validity of a virus before sending out any warnings.  Nearly ALL the virus warnings I have received have been hoaxes.

People with cable modems and DSL lines need to be extra cautious about security.  For them a router with a firewall feature is a good investment. Check with your ISP to recommend a good one.

Good luck.

End of Article

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