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.
Comment:
SpyHeal is a rogue antispyware which display false detections on user's machine and force them to buy the product.
Screenshots:
SpyHeal
Showing False Detections
From the SpyHeal website
Poor Uninstaller which does not remove Spyheal.exe from user's machine
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