Eight types of Spyware: Adware, Snoopware, Cookies

1. Spyware: I Spy with My Little App
Spyware includes programs that can record what you do on your computer and share that information with a stranger via an Internet connection. Some can watch and record your web-surfing habits. Some log everything you type. Spyware can also capture user IDs and passwords. It might have the ability to see where you have been on the Web. If there's information on your computer that is of interest to someone and can make them a little money, there's probably a spyware program to capture it.

2. Adware: Attack of the Pop-ups
Adware is equally annoying because it not only spies on you, but then it shows you ads. Some adware spies on you because its mission is to show you ads customized to your tastes, usually via pop-up ads on your computer's desktop. Sometimes adware is a legitimate part of a free program. Software publishers often bundle adware in with free programs they offer, using it as a revenue source. Many warn you of the adware during installation in the End User License Agreement, also referred to as an EULA. (That term always make me think of a slightly portly aunt that you hate to kiss but who makes good cupcakes.)

3. Snoopware: I Wanna Know What You're Up To!
Snoopware watches your computer habits on behalf of someone else, usually someone you know. This can include parental monitoring softwareprograms designed to track children's computer habits. One of the most popular uses of snoopware is to track the behavior of a spouse. Usually it's purchased by wives who suspect their husbands are up to no good on the Internet, though it can equally track wives who might be sending the pool boy spicy emails.

4. Browser Hijackers: Turn This Browser Around, We're Going to Cuba.com
Browser hijackers are perhaps the most malicious spyware programs because they are so hard to remove. When you first open your web browser your home page pops open. Most people set this to Google.com, a news site, or their favorite web page. Browser hijackers override this setting and reset a browser's homepage to one of their choosing, usually a commercial web page. Why? Well, the link to the web page they set can be something called an affiliate link. The hijacker's author makes money when you are sent to the affiliate link.

5. Key Loggers: Snooping on Your Typing Skills
Key loggers can either be hardware or software. The software versions run secretly in a computer's memory and capture everything typed into the computer. It then saves it for later analysis by a third party. A key logger can also be a piece of hardware that is attached between a computer's keyboard and its keyboard port.

6. Dialers: Dial In, Dial Out, Dial Often
Dialers are programs that initialize a computer's modem and call out silently to a toll line and connect to a web page. It's the computer equivalent of one of those psychic help lines they advertise on TV. The longer you are connected the more you pay. The one difference is the "psychics" on the destination site you're connected to by dialers are not so psychic and they seem to have forgotten their clothes.

7. Trojan Horses: Pretty Ponies with Deadly Insides
I list Trojan horses here because anti-spyware programs often detect and issue spyware signatures for them. A Trojan horse, named after the famous hollow wooden horse that got the Greeks secretly into Troy, is an innocent-looking innocuous program that contains a virus or some other nasty malware in its belly (for more on Trojan Horses, see Chapter 1, "Viruses: Attacks of the Malicious Programs").

8. Cookies: Does My Oreo Have a Tape Recorder in It?
Cookies are tiny text files stored on your computer (see Figure 2.5) to help websites track your movements through their pages. They also record sign-in data and other site logon information that allows easy access to the site when you come back later. Web shopping baskets also use cookies to keep track of what you have selected to buy as you move from page to page on a shopping site. [Absolute Beginner's Guide To: Security, Spam, Spyware & Viruses, Andy Walker, 2005]