From our Glossary
HACKER, ATTACKER, or INTRUDER: These terms are applied to the people who seek to exploit weaknesses in software and computer systems for their own gain. Although their intentions are sometimes fairly benign and motivated solely by curiosity, their actions are typically in violation of the intended use of the systems they are exploiting. The results can range from mere mischief (creating a virus with no intentionally negative impact) to malicious activity (stealing or altering information).
MALICIOUS CODE: This category includes code such as viruses, worms, and Trojan horses. Although some people use these terms interchangeably, they have unique characteristics.
SPYWARE: Spyware was originally, not designed to do mischief, but rather to gather information. More recently, spyware, or adware, has changed into an invader of your privacy. It examines programs and cookies on your computer looking for items used to either gain data from your computer or track your Internet use. A spyware checker is a program designed to protect your personal information. The most common type of spyware, more properly termed adware, generates pop-up and other ads.
TROJAN HORSE: A Trojan horse program is software that claims to be one thing while in fact doing something different behind the scenes. For example, a program that claims it will speed up your computer may actually be sending confidential information to a remote intruder.
VIRUS CHECKER: A virus checker or virus protection is a program that runs continuously whenever your computer is on. It monitors the contents of e-mail attachments as well as programs that run on your computer. It detects and disarms viruses and prevents damage to your computer before they start trouble.