Anti-Virus

There are three main categories of downright hostile programs: viruses, worms, and Trojan horses. I use the term “virus” or “viruses” to refer to all three categories throughout this article. The primary function of a virus is to spread itself to other computers typically through email or directly through a network or the Internet. A secondary function of a virus may be to open a back door to your computer so that someone else (probably the virus author) can access it from the Internet. This is very common. First, a virus author will try to infect thousands of computers and have them in “standby mode” waiting for marching orders. Computers that have this kind of infection are called “zombies”. Then the author will give a command to all of the computers to simultaneously flood a particular Internet site with network traffic so the site is inaccessible to the rest of the world. This is called a “Denial Of Service” attack or DoS attack.

You’ve probably heard of this being reported in the news. Viruses may also randomly display some juvenile message, play music, or perform some other shenanigans. In addition, they can be malicious enough to delete files or otherwise wreak havoc on your hard drive. In the worst-case scenario, a virus can cause you to lose all data on your hard drive. An average scenario is that the virus creates a breach of security that allows others to take over you computer. In the best-case scenario, a non-malicious virus will simply run in the background, bog your computer down, and chew up network bandwidth. What’s the bottom line? All viruses are bad news and should be prevented from entering your system.

Does your computer have an antivirus application installed? If not, get one! Antivirus software is a very necessary evil in today’s computing environment. This is especially true if your computer can access the Internet or exchange data with other computers via a network, dial-up connection, removable media (floppy disk, zip disk, flash memory card, etc), or some other method. There are several major antivirus applications available today including Norton Antivirus (Symantec), VirusScan (McAfee), PC-Cillan (Trend-Micro), InoculateIT (Computer Associates), and AVG Antivirus (Grisoft). My personal favorite is AVG Antivirus, which can be obtained from www.grisoft.com. For more details about AVG AntiVirus, click here.

Next, check and make sure that your virus definitions are up to date. Simply having antivirus software installed doesn’t protect your computer! I can’t count how many computers that had outdated antivirus running from which I have had to remove viruses.

Antivirus software is reactive. In other words, your antivirus application can’t recognize a particular virus until the virus has been previously identified by the antivirus software company. First, the antivirus software company has to get a sample of the virus and analyze it. Then the antivirus software company creates a “virus definition” for that particular virus that contains information (or a fingerprint) used to identify the virus. This virus definition must then be downloaded by your antivirus application and stored in its virus database. At this point, your computer is protected from that particular virus while your antivirus application is running. Have you ever gone to the post office and see the list of the FBI’s most wanted hanging on the wall? Each criminal is listed on a separate sheet, which gives details to help identify the criminal. Each sheet is like a “virus definition”. All of the sheets together are like the virus database.

To determine whether your antivirus application is using the latest updates, you need to look for the date that the virus definitions were last updated. This information is accessed from somewhere within the antivirus application and is called “Virus Database Release Date”, “Virus Definitions Date”, “Date last updated”, or some other similar phrase. If this date is anything less than today’s date, run a manual update to make sure that there aren’t any newer updates available. If you run a manual update and get a message that says something like “no updates available” or “your program is up to date” then you know that you have the latest virus definitions.

If you get a message that states something like “Your subscription has expired”, it’s time to get some new antivirus software! Typically, antivirus software comes with a subscription that last 90 days, 1 year, or 2 years. When the subscription expires, you can’t download any new virus definitions. You have two choices here. You can renew your subscription for your existing antivirus application, or you can purchase a different antivirus application. If you like your current antivirus application, then renew it. Most of the antivirus companies will allow you to renew online with a credit card. If you don’t like your current antivirus application or if you just feel like trying something new, go to www.grisoft.com and give AVG antivirus a try. If you do decide to change your antivirus application, make sure that you uninstall your old antivirus application before installing the new one. Having two different antivirus applications running simultaneously will sometimes cause problems.

When you are sure that your antivirus software is up to date, perform a full scan of your computer. This usually takes several minutes. If any viruses are found, make sure that they are removed. Most viruses can be removed successfully by your antivirus application. However, some are a little tougher and can’t be completely removed this way. If this is the case, follow the instructions provided by your antivirus application. Sometimes the antivirus company will provide a free utility that you can download and use to remove a particular virus. Once the virus is removed, run a full scan again. Repeat this process until the scan reports that no viruses were found.

It’s important to note that even if you update your antivirus application every day, it’s still possible to have a new virus infect your computer. Your antivirus application can only protect your computer against viruses that have previously been identified by the antivirus company. When a new virus is released, it spreads across the globe very quickly due to the Internet. It usually takes the antivirus companies about 24 hours to identify a new virus and release a virus definition for it. If your computer is hit in that first 24 hours, your antivirus application won’t be “aware” of the virus and therefore won’t be able to protect your computer. Therefore, it’s very important to not open suspicious email attachments even if your antivirus application is up to date.