Explanation/Notes: Malicious Web site operators may set up a site that purports to offer something of value or the possibility of winning a prize. To register, a visitor to the site must enter an email address, username, and password. Since many people use the same or similar sign-on information repeatedly, the malicious Web site operator will attempt to use the chosen password and variations of it for attacking the target's work- or home-computer system. The visitor's work computer can sometimes be identified by the email address entered during the registration process.