Virus Prevention 101

Blaster, Welchia, Sobig, W32, Backdoor, Trojan, Melissa, Klez, Worm, Loveletter, Nimda… Do these names sound Familiar?

Aug 19, 2003

By Greg Richburg, MCSE
Netricks, Inc.

Blaster, Welchia, Sobig, W32, Backdoor, Trojan, Melissa, Klez, Worm, Loveletter, Nimda… Do these names sound Familiar?

Have you been as bothered by viruses this past year as I have? Does it seem like there are more viruses, worms and Trojans out now then ever before? It is only getting worse.

For the general public, "virus" has become a catchall term for any unwanted program that spreads from computer-to-computer; yet, in reality, there are differences between viruses, worms and Trojan horses.

Worms reside in active memory, are self replicating, and usually use native operating system components to do so. Trojans are programs in which malicious or harmful code is contained inside apparently harmless programming or data. Viruses are pieces of programming code that cause some unexpected and usually undesirable event. All of them can really ruin your day.

Everyone who uses a computer can catch a virus. Borrowing disks, swapping floppies, moving data from one machine to another, sending and receiving e-mail, the list goes on. If you use the Internet, your chances increase, even if you use a dial-up modem. Some viruses can be caught just by visiting infected websites.

There are over 50,000 active viruses today. But on any given day, only a few hundred viruses pose a serious threat to your computer. Some of the most destructiveMelissa, Love Letter, and more recent Blastercaused millions of dollars in damage.

Many systems and networks never completely recover from a virus attack. Though a virus protection program is imperative to your computer’s health, it does not in any way ensure your safety.

To be effective antivirus programs require proper setup and frequent s. Newer applications have built in rs and if installed properly require almost mo maintenance. However, older programs required user interaction to get the latest definitions.

In a corporate environment, a system can be installed in which the users have no dealings with the antivirus application at all. All monitoring is done by the network administrator and on the server level.

A primary server with groups and group leaders can be defined during setup. Specific systems are assigned to groups usually based on their physical location. The primary server automatically gets its s from the antivirus vendor. The group leaders then get their s from the primary server and distribute them to all the members on a daily basis. The network administrator monitors one system that can control the scanning, updating and managing for the entire network.

How can you stay protected?

Install anti-virus software and keep the virus definitions up to date.
Don't automatically open attachments and make sure your email program doesn't do so automatically.
Scan all e-mail attachments.
Configure your anti-virus software to boot automatically on start-up and run at all times.
Avoid downloading files you can't be sure are safe. This includes freeware, screensavers, games, and any other executable program.
Don’t use floppies, but if you must, scan them before using them.
Educate yourself and your users to learn how to spot viruses.

Greg Richburg a Microsoft Certified Systems Engineer and the owner of Netricks, Inc. a network consulting, web design and hosting company located in Fresno, CA. Visit Netricks at http://www.netricks.com.