Despite its name, the term "spyware" doesn't refer to something used by undercover operatives, but rather by the advertising industry. In fact, spyware is also known as "adware." It refers to a category of software that, when installed on your computer, may send you pop-up ads, redirect your browser to certain web sites, or monitor the web sites that you visit. Some extreme, invasive versions of spyware may track exactly what keys you type. Attackers may also use spyware for malicious purposes.

Because of the extra processing, spyware may cause your computer to become slow or sluggish. There are also privacy implications:

• What information is being gathered?
• Who is receiving it?
• How is it being used?

To avoid unintentionally installing it yourself, follow these good security practices:

• Don't click on links within pop-up windows - Because pop-up windows are often a product of spyware, clicking on the window may install spyware software on your computer. To close the pop-up window, click on the "X" icon in the titlebar instead of a "close" link within the window.
• Choose "no" when asked unexpected questions - Be wary of unexpected dialog boxes asking whether you want to run a particular program or perform another type of task. Always select "no" or "cancel," or close the dialog box by clicking the "X" icon in the titlebar.
• Be wary of free downloadable software - There are many sites that offer customized toolbars or other features that appeal to users. Don't download programs from sites you don't trust, and realize that you may be exposing your computer to spyware by downloading some of these programs.
• Don't follow email links claiming to offer anti-spyware software - Like email viruses, the links may serve the opposite purpose and actually install the spyware it claims to be eliminating.

As an additional good security practice, especially if you are concerned that you might have spyware on your machine and want to minimize the impact, consider taking the following action:

• Adjust your browser preferences to limit pop-up windows and cookies - Pop-up windows are often generated by some kind of scripting or active content. Adjusting the settings within your browser to reduce or prevent scripting or active content may reduce the number of pop-up windows that appear. Some browsers offer a specific option to block or limit pop-up windows. Certain types of cookies are sometimes considered spyware because they reveal what web pages you have visited. You can adjust your privacy settings to only allow cookies for the web site you are visiting.