Potentially unwanted program

A potentially unwanted program (PUP) is software which has been bundled with another installer. This is usually a demo version of some program they are attempting to sell. When someone goes to install a certain desired program, the PUP is installed as well, with or without the user's consent. These unwanted add-ons are also sometimes called bloatware, since they can fill (bloat) a person's system with useless software. People would be well advised to watch carefully what is going on when downloading software. The screens associated with software downloads are often set to "yes" for these things, and the ways to decline such installations are often obscure. You only install a given piece of software once—it's worth taking the time to pay close attention to that is going on.

Kinds of Potentially Unwanted Programs

• Adware (Like Superfish) - Insert advertisements into web pages you view, or even starts popup ads on your computer itself
• Mirror/Local Proxy - Mirrors or redirects all internet traffic through itself so it may build a profile of the user, which may be used for targeted marketing or sold
• Web browser Hijacking - Forcibly alters browser settings to earn the distributor money, usually by changing the home page and/or default search engine. This sort of thing is extremely common.
• Dialer - A largely out-of-date attack intended for dial-up internet connections (or now, Cellular phones) which dials out to unwanted destinations for the purpose of wasting the owners data transfer allowance.

Examples

• Adware is often installed as a PUP, sometimes with full programs, and sometimes with browser extensions
• Adobe has attached a PUP to its Flash Player and Shockwave products for years. This is one of the ways Google Chrome took over the web browser market
• Conduit's web browser toolbar is sometimes proclaimed as "popular," but is often installed as bloatware.