Viruses, Worms, and Trojans, Oh My!

 

There are always new warnings about the latest threats to computer users; viruses with weird names, worms, and...Trojan Horses? In this article, we'll discuss what each of these items are, and a bit about how to avoid them, and, if your computer's feeling a bit ill, how to get rid of them.

WHAT ARE VIRUSES (VIRII)?

According to Wikipedia, a virus is a program which can be transmitted between computers via networks (especially the Internet) or removable storage such as CDs, usb drives, floppy disks, etc., generally without the knowledge or consent of the recipient.
Viruses can damage your software, hardware, or your data files. Just as human viruses vary in severity, computer viruses can range from annoying to fatal.
Viruses generally spread with human intervention, such as sharing a file or sending an e-mail. This is in contrast to Worms.

WHAT ARE WORMS?

Worms are self-replicating programs, similar to viruses. A Worm is self-contained, and does not require another program to propagate itself. Worms spread without human intervention, usually by taking advantage of the systems used by the computer to transfer files and information. Once you get a Worm on your system, it works by itself. The most common way that Worms travel is through e-mail. When your computer is infected by a worm, it helps itself to your e-mail software, sending messages to everyone in your address book. Their computers would then do the same thing, causing an exponential volume of e-mail traffic across the Internet.This "domino effect" causes increased web traffic, and can slow the entire Web to a crawl. This is why you may hear on the news about a particular company being hit by a worm. If they are targeted by a Worm (meaning their e-mail addresses get hit especially hard), their website and network can be reduced to a quivering mass of jelly, and they can't conduct business.

WHAT ARE TROJANS?

Trojans, or Trojan Horses, are software disguised as harmless, developed to allow unauthorized access to a computer through a backdoor (e.g. Internet port). (Wikipedia) If you remember your ancient history, when the Greeks invaded Troy, they hid themselves in a giant wooden horse, which the Trojans thought was a gift. When they weren't looking, the Greeks came out and took over the place. This is exactly what a Trojan does on your computer. Trojans spread when people are lured into opening a program that they think is legitimate. A good example is an e-mail from Microsoft claiming to contain urgent security updates. That can sound pretty scary, huh? Companies like Microsoft, your bank, the government, etc. will never send an e-mail with an attachment. Trojans can also come from programs that you download. NEVER download from locations that you don't know and trust. Always go to legitimate sources for downloads.

Now that we know the differences between these types of threats, let's look at how to get rid of them.