Unfortunately, you’ll find little consistency in the use of terms and descriptions when you read articles about unsafe or unwanted software Some sources use the word spyware as a broad brush that covers even the most innocuous browser add-ons In this book, we use the term deceptive software to refer to a wide continuum of programs, scripts, and browser add-ons that are typically installed without full disclosure of exactly how they work Programs in this category interfere with legitimate requests to retrieve information from some websites and, in extreme cases, interfere with the operation of the computer itself Some developers go out of their way to hide the fact that their program is installed at all and make the process of removing it as difficult as possible.
Depending on how a particular program or add-on works, you may hear it referred to by a number of specialized terms:
+ Spyware is the term used to describe programs that gather information about you and your browsing activities without your knowledge and informed consent These programs can store that information and use it to modify your computer’s behavior, or they can send the data to the software developer or to a third party.
+ Adware refers to a class of programs that display advertisements—usually in popup windows, on the desktop, or in the browser window These programs often contain spyware-like features in that they monitor your movements around theweb so that they can provide ads that are ostensibly related to your interests.
+ Home-page hijackers are scripts or programs that modify your browser settings to change your default home page This type of exploit often affects search settings as well Some especially egregious offenders modify the registry or place files on the affected computer that block the user’s ability to change these settings The new home page is often disguised to look like a web portal or a legitimate search page, although a minority of programs in this category send the victim to X-rated sites.
In all three categories, the motive for infecting your computer is usually economic, with the owner receiving cash for referrals to webpages that originate from the stealthily installed program Other examples of deceptive software—less common but more dangerous— include dialers, which configure a computer to make unsolicited (and usually expensive) dial-up connections, and Trojan horses, which allow an intruder to take over a compromised computer and use it to attack other computers or forward spam.
