Summary

The 'UltraCool' joke is a standalone application. When executed it first asks to enter first and last names of a user. Then it outputs the following message:

  Error

  This application stopped responding to the computer.
     A LOW level Hard Disk format will procede in
      27 seconds if cancel button in not pressed

      WARNING: THIS WILL DELETE ALL INFORMATION
              STORED ON YOUR HARD DRIVE

Additional Details

This dialog has a 'Cancel' button. After that the countdown starts. The 'Cancel' button can't be clicked because it moves away when mouse cursor appears near it. When the counter reaches zero the screen goes blank for a second and then the joke shows a message in big letters 'Just Kidding...'. Shortly after that there appears 'Done' button. After this button is clicked the joke passes control to the system.

The joke is written in Visual Basic.

[Analysis: Alexey Podrezov; F-Secure]