The 'Joke.Win.Stript' is a simple joke program.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
Being run it imitates Windows having fatal errors by opening series of messageboxes with error messages. After that another messagebox appears with the text:
Are you sure you want to format the hard drive ?
There's only 'OK' button in this messagebox, so the user has to press it anyway. Then the joke opens another dialog with hard disk format progress indicator and the text:
Formatting hard disk. Push Escape to cancel.
If you press 'Cancel' button there appears a messagebox with the text: "Necessary files not found!". After that or when progress indicator reaches 100%, the screen is filled with garbage and the joke waits for keypress. Then the final messagebox appears with the following text:
I scared you, didn't I ?
English and German versions of this joke exists.
Technical Details: Alexey Podrezov, F-Secure