Written By:
Date Posted: October 16, 2001

You have been stoned.

Ugh, I remembered when I got that one. It was over 12 years ago, when floppy disks were the rage. It was my first computer, and I never knew that viruses for computers existed. I don't remember what the "Stoned" virus did, but I did know that it was transferable.

Viruses have gotten more complex and malicious over the years, and it's not really all that hard to contract one on your PC. Viruses, worms, trojans, they're separate entities, but they all do the same thing, ...wreak havoc on your computer. I'll start off by giving a small explanation of each major computer threat.

Computer Virus

A computer virus is a program that "infects" your computer. Usually, unless you enjoy reformatting and wiping off your hard drive, a virus infects your computer when you execute an (unexpectedly) infected file. A virus contains it's own set of programmed functions, which varies depending on what the creator wanted it to do. A virus speads by infecting other files on your computer, and propagates when you transfer an infected file to another via email, or sneaker mail (removable media). It then does the same to the next computer, and the one after that.

Some viruses are relatively harmless. They may pop up a message saying "Hello", or something worse. They can corrupt files, especially system files, rendering a PC unbootable, or they can actually disrupt the master boot record of your hard drive, forcing a fdisk /mbr and reformat. A computer virus can be a program that performs whatever role it's been assigned instantly, or timed for a specific time and/or date.

Trojan Horses

A trojan horse borrows it's discription from the story of Troy, where soldiers hid in a huge wooden horse. They waited until the citezens of Troy brought it in past the security gates, and the soldiers stormed out to take the city.

Like the story, in the computer world, a trojan horse is a malicious program that does not appear to be obvious. There are several trojans out there, and an infamous one is the dreaded Back Orifice. Many times, nobody is aware they've been infected, and trojans are hidden in almost anything interactive in nature.

Back Orifice opens various ports (like doors to your house), and allows a hacker a way into your computer. Luckily, for some of you, it only targets Windows operating systems. .

Once infected, a hacker can easily gain control over your system, doing everything you can, except he/she can do it remotely. Delete files, open and close your CD drives, steal personal info, log keystrokes, you name it.

It spreads like a virus, but unlike a virus, which is usually obvious in appearance, a trojan is tougher to spot.

Worms

A worm, though infectious, differs from trojans and viruses. A worm rarely damages actual system files, but rather, it infects your computer with the intention of replicating itself and spread to others. It hunts the local network you're connected to, be it LAN or Internet, and scours for other computers with security issues to exploit.

It's this replication that is the problem, as for any program to work, it needs processor usage and time. As it spreads, it uses up network bandwidth. In the case of "Code Red" earlier in the year, there was so much traffic cause by the spreading, servers went down, and the Internet slowed to a crawl.

Some worms, when it reaches critical mass, may await a certain date, and network flood a particular website. This was the case with a variation of Code Red, when the whitehouse.gov domain was the target.

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