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Worms and Viruses

Beware of Worms and Viruses!!!

Computer viruses are called "viruses" because they work a lot like biological viruses do -- passing from one host (machine) to another just as a biological virus passes from person to person.

And like their biological analogues, digital viruses replicate themselves and infect others (without the permission or knowledge of the user) by piggybacking on some kind of carrier.

Types of electronic infections

The news media employ the term "virus" to describe several different types of electronic infections. The most common types:

Computer Virus Information

Virus - A small program, which can be benign or malicious, that is concealed within another program. Each time the carrier program runs, the virus runs, too, and has the chance to reproduce itself or wreak havoc.

  • An email virus replicates by automatically mailing itself to dozens of people in the victim's email address book.
  • Other types of viruses include boot sector viruses, companion viruses, time bombs, and macro viruses.

Worm - A small piece of malicious software that can grow exponentially through computer networks. Once it's on a computer, it scans the network for another machine with a specific security vulnerability. When it finds one, it exploits the weakness to copy itself to the new machine, and then starts replicating from there, as well. Worms require no user action to do their damage.
Trojan Horse - A file that claims to be something desirable but is in fact malicious. It may claim to be a game or screen saver, for example, but instead does significant damage when you run it, such as erasing your hard drive. Trojan horses have no way to replicate automatically.

How to use your anti-virus program

Graphic of red hand on yellow triangle and the words Many people don't realize that there is a proper way to use an anti-virus program. Just having anti-virus software loaded on your computer is not enough; you must keep the software up-to-date, run virus scans, quarantine files as needed, and renew your virus definitions file.

If you don't, you won't get the benefit of the anti-virus protection. If that sounds like a lot, don't panic: most modern anti-virus software allows you to automate most of the work.

Follow all of the steps below to get the most benefit from your anti-virus software:

  • Keep your anti-virus program running all the time to identify new threats as they come in. This will protect your machine from becoming infected in the first place. For example, if your anti-virus program is running when you receive an email with an attachment, it will protect you by scanning the attachment before you open it. If the attachment contains a virus, the anti-virus program will warn you before you open it and the infection mechanism is activated. Most anti-virus software runs constantly by default -- but check yours to make sure.
  • Update your virus definitions daily. Your anti-virus program knows how to spot incoming contagions because it has a virus definitions file -- a database of known virus patterns -- to use as a reference. If its virus definitions file is out of date, your program has no way to recognize newly-created bugs! Most anti-viruses can be configured to check for new virus definitions automatically, so you should set yours to check every day. Infections spread across the Internet like wildfire, in days or even hours, so you should make sure your definitions are as current as possible.
  • Scan your hard drive for viruses daily to identify any viruses that may already be be present. Even with your anti-virus program monitoring your machine constantly, it is still possible for infections to creep in. Most anti-virus programs can be set to scan your computer automatically -- but if a scan finds infected or suspicious files, you will have to review the results and decide what to do with the identified files. You may opt to ignore, remove, or quarantine them. When in doubt, Google the name of the questionable file before deleting it.
  • Renew your anti-virus subscriptions as needed to ensure ongoing protection. Many computers come with trial anti-virus software that expires after a short time -- a few months, say, or a year. Make sure you renew your subscription in a timely fashion, or you will no longer be protected from new viruses that emerge.

Anti-virus software options

Most computers come with at least a trial version of anti-virus software. Once the subscription runs out, though, you'll have to purchase a permanent one, or download a free anti-virus program of some kind.

There are many vendors who produce anti-virus software, and deciding which one to choose can be daunting. All anti-virus software performs the same function, so your decision may be driven by particular features like spyware and adware protection, availability, or price. Investigate what each product offers to see which one best meets your needs. Some of the more widely used anti-virus programs:

How to get rid of electronic infections

If you feel that your computer has been hacked or infected by a virus or worm, immediately disconnect it from the network or Internet (unplug the phone, DSL, or cable line) to keep it from getting worse or infecting others.

Then, use another, non-infected computer to download up-to-date anti-virus or anti-malware software and save it onto a portable memory device such as a CD, DVD, thumb drive or "memory key." Use the portable device to run the anti-virus program on the infected computer to clean up the problem.

Once you've done this, prevent re-infection by making sure your operating system is up-to-date and configuring your anti-virus, anti-spyware, and firewall software to automatically update and run constantly in the background. 

ZoneAlarm Firewall (Free Version)

More tips to stay virus-free

By now, most people know not to open email attachments that are from unfamiliar senders -- and even to use caution when opening email attachments from friends and family. If you are not expecting an attachment, ask before you open!

Beyond that, the best way to defend yourself from all electronic infections (besides using your anti-virus program effectively) is to keep your operating system and application software up-to-date with all security patches, and to back up critical data frequently.

  • Keep your operating system up-to-date. Many people skip this critical step. Don't be one of them. Be sure your computer is configured to automatically download and install any OS updates, so you don't have to remember to keep checking! Windows users, check here. Mac OS X users, open System Preferences and select the icon for "Software Update" -- it should be set to check automatically every week.
  • Secure your application software. Internet browsers and office productivity applications (word processors, spreadsheets, etc.) are sometimes vulnerable to exposure of your private information. Software manufacturers regularly provide updates to these kinds of programs. Some updates can change the behavior of your programs, and some cannot be removed without reinstalling the software from scratch, so you need to read carefully any information the vendor provides regarding the update, and decide if it is appropriate for your situation.
  • Make frequent backups of critical files. If you get a virus or other electronic infection and your system crashes or has to be wiped clean, you'll be glad you made backups. Make copies of essential documents, photos, music files -- anything you would be distraught to lose. You can make backups using a variety of media -- CDs, DVDs, thumb drives or "memory keys," external hard drives, a server or Internet site that allows you to store documents, etc. You should also be sure to keep any software CDs that came with your computer, in case your hard drive is ever wiped clean and you have to reinstall everything from scratch.