Malware (short for MALicious SoftWARE) is a prominent threat in our increasingly connected world. In short, malware is any program created with the purpose of causing damage to a computer system or compromising the security of a computer system. Pretty much all the "internet nasties" you've heard of fall into the broad category of malware. These include viruses, worms, Trojans, keylogger, spyware, adware. Even SPAM might be considered associated with malware, though not malware itself, since it can be the means by which hackers get those other types of programs onto your system.

Viruses and worms function in the computer world much like they do in the real world in that they replicate themselves and pass from one carrier to another (be that a computer or a person, depending on which type you're talking about). They can either spread on their own, or after the user takes some pre-determined action like opening an email, running a program, etc. It turns out that most of these programs are written to take advantage of Microsoft Windows Operating system rather than Macs or Unix/Linux systems. But that has a lot to do with the fact that there are many more Windows users than other types of operating systems.

Trojans get their name from the famous story of the Trojan Horse and operate in a similar fashion. Trojans get onto your system and hide there by appearing to be something else, a seemingly harmless file that when run, contains a "little extra something" that the user definitely isn't expecting. The end result varies depending on what's "inside the horse", to continue the analogy. It might be a program that deletes everything on your C: drive, it might install another program or change an existing program. This is how spyware is passed along much of the time. For instance, you download a free screensaver, install it and at the same time, also install a program that monitors your keystrokes and sends that info back to a third party via the internet.

Spyware and adware are among the biggest threats now. They also create the biggest headaches for security experts since so many computer problems are now found to be caused by spyware. Spyware creators are usually motivated by profit rather than purely malicious desires as might be the case with a virus/worm creator. Spyware and adware are typically used to control a computer and drive the user to websites which the creator will profit from or for displaying advertising via popups, popunders, or other means.

Spyware is usually installed as part of another software package without the user's consent, or sometimes with their consent though they may not realized it. Often times, this implied consent is buried in the End User License Agreement (EULA) which the user must agree to prior to installing the program. By not reading or understanding the terms contained in the EULA, the user might be unintentionally agreeing to have spyware installed. Once installed, this might become a means for other spyware programs to also end up on that computer.

Malware certainly is a threat that you should be aware of, but there are measures you can take to minimize the chances your computer will be infected. There are three essential items you should have for good computer security. First, a good firewall, either a software or hardware firewall will do. Second, an anti-virus program. Third, an anti-spyware program or spyware remover. Ideally with these last two items, the programs will run on your computer from startup to shutdown, will monitor your programs as they start up, and will automatically update themselves with the latest threat database. That way, you can rest assured your computer is up-to-date and not have to spend unnecessary time managing your computer's security.