These are usually anti-spyware or security software applications that use various forms of deception and/or unethical means or show a history of negligent false positives to goad the end user to make a purchase.
In some cases these applications maybe downloaded with some form of unwanted software at which point the rogue application is offered to the customer as a way to remove the unwanted software.
WinAntivirus may collect the user's information.
They may disclose collected user information to advertisers and/or business partners.
Known to issue questionable false positives on clean installs of Windows XP.
Win Antivirus 2007
Win Antivirus 2007 more