Malware: Computing's Dirty Dozen

 by: Joel Walsh

It seems that no sooner do you feel safe turning on your computer than you hear on the news about a new kind of internet security threat. Usually, the security threat is some kind of malware (though the term "security threat" no doubt sells more newspapers).

What is malware? Malware is exactly what its name implies: mal (meaning bad, in the sense of malignant or malicious rather than just poorly done) ware (short for software). More specifically, malware is software that does not benefit the computer's owner, and may even harm it, and so is purely parasitic.

The Many Faces of Malware

According to Wikipedia, there are in fact eleven distinct types of malware, and even more sub-types of each.

1. Viruses. The malware that's on the news so much, even your grandmother knows what it is. You probably already have heard plenty about why this kind of software is bad for you, so there's no need to belabor the point.

2. Worms. Slight variation on viruses. The difference between viruses and worms is that viruses hide inside the files of real computer programs (for instance, the macros in Word or the VBScript in many other Microsoft applications), while worms do not infect a file or program, but rather stand on their own.

3. Wabbits.Be honest: had you ever even heard of wabbits before (outside of Warner Bros. cartoons)? According to Wikipedia, wabbits are in fact rare, and it's not hard to see why: they don't do anything to spread to other machines. A wabbit, like a virus, replicates itself, but it does not have any instructions to email itself or pass itself through a computer network in order to infect other machines. The least ambitious of all malware, it is content simply to focus on utterly devastating a single machine.

4. Trojans. Arguably the most dangerous kind of malware, at least from a social standpoint. While Trojans rarely destroy computers or even files, that's only because they have bigger targets: your financial information, your computer's system resources, and sometimes even massive denial-of-service attacks launched by having thousands of computers all try to connect to a web server at the same time. Trojans can even

5. Spyware. In another instance of creative software naming, spyware is software that spies on you, often tracking your internet activities in order to serve you advertising. (Yes, it's possible to be both adware and spyware at the same time.)

6. Backdoors. Backdoors are much the same as Trojans or worms, except that they do something different: they open a "backdoor" onto a computer, providing a network connection for hackers or other malware to enter or for viruses or spam to be sent out through.

7. Exploits. Exploits attack specific security vulnerabilities. You know how Microsoft is always announcing new updates for its operating system? Often enough the updates are really trying to close the security hole targeted in a newly discovered exploit.

8. Rootkit. The malware most likely to have a human touch, rootkits are installed by crackers (bad hackers) on other people's computers. The rootkit is designed to camouflage itself in a system's core processes so as to go undetected. It is the hardest of all malware to detect and therefore to remove