Juan Murillo Consulting

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4 - Viruses: What are they and how can you protect yourself?

In previous Computer Corners we’ve talked about what allows computers to work properly, now we’re going to begin discussing some of the things that cause computers to fail or not perform as intended. We’ll begin with the dreaded computer virus.

If you’ve used computers for any length of time or even just paid attention to the six o’clock news, you’ve undoubtedly heard people talk about viruses. They’ve been blamed for everything from lost data to citywide blackouts. So just what are they and why does their simple mention strike fear into hearts of computer users everywhere?

Computer viruses are created by people, often for no better reason than notoriety among their peers. They are called viruses because they share some of their biological namesake’s traits. For example, the essential purpose of both is to replicate themselves and neither can do this without the aid of a host. A biological virus uses the host’s cell to replicate itself and a computer virus attaches itself to a computer program that, when launched, allows the virus to perform any number of actions, not the least of which is to propagate to other files and/or computers. 

One of the first computer viruses was created in Pakistan in 1986. It infected floppy disks’ boot sectors - the portion of the disk containing instructions on how and where to access information on the disk. Aptly named “Brain”, it was the first of it’s kind to employ “stealth” technology to hide itself from detection; it took nearly two years to develop an “immunization”.

As personal computers (PC’s) increased in number and complexity so did the viruses that sought to manipulate them. With the advent the Internet and proliferation of e-mail communications, computer virus makers found an enticing new avenue to exploit. Combine this ever-expanding vehicle with the temptation to cause mayhem and the end result is today’s multi-billion dollar “Antivirus” enterprise.

In the best case, the extent of the damage can be limited to having to apologize to the clients, friends and family in your address book. However, more destructive viruses can wreak havoc on your computer and/or your company’s network.

There are essentially three ways your computer can be infected by a virus; the most common of which these days is via e-mail. An e-mail virus is sent to its victim via an e-mail attachment (a file “attached” to an e-mail). Depending on the sophistication of the virus, it may be “activated” by opening the e-mail alone or its activation may require that the attachment be opened. In either case, upon activation the virus usually replicates by automatically mailing itself to all the people in the victim's e-mail address book.

Viruses are also created to find and take advantage of security holes in computer networks. These “worms”, as they’ve been labeled, are small pieces of software that scan the network for another computer that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.

Finally, viruses can find there way into your computer via a “Trojan Horse”. The Trojan is simply a computer program that claims to be one thing, a game for instance, but when executed it performs any number of damaging actions on your computer instead. Given that you’ve launched the program, you’ve in essence given the program “permission” to do what it does. It may erase your hard disk, capture and transmit confidential information to other computers or manipulate operating system files causing your computer to act erratically. Trojan Horses are usually spread through downloads from the Internet or removable media such as floppy discs and CD-ROMs. They typically have no way to replicate automatically; they require action on behalf of the user to propagate and do damage.

So what can you do to protect yourself? As is the case with biological viruses, an ounce of prevention is worth a pound of cure. Just as you would inoculate yourself against the flu virus, you should immunize your computer by installing an “Antivirus” application such as Symantec’s Norton Anitvirus® or McAfee’s Virus Scan®. Be advised however that installation of an antivirus application alone will not protect you against new viruses. As new viruses are created and unleashed almost daily, it is VITAL that you keep your antivirus applications up to date by regularly downloading and installing the most recent virus definitions.

The virus definitions allow your antivirus application to identify and fix or quarantine new viruses before they can replicate and/or do damage. Both Symantec and McAfee provide an option to automatically check for, download and install their most current definitions as part of their application’s installation and configuration.

If you are in a network or corporate environment I highly recommend that you obtain professional assistance in the selection, installation and configuration of an “Enterprise” level antivirus solution. The initial cost outlay will be miniscule in comparison to the cost of recovering from a virus that destroys company data, publicizes confidential information or renders your e-mail systems useless. For more information on viruses or how to protect yourself, please feel free to contact me directly.

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