A joke program
is an ordinary executable program with normally no malicious intent.
Virus authors create joke programs for making fun of computer users.
They do not intend to destroy data but some inexperienced users
may inadvertently perform actions that can lead to data loss (such
as restoring files from an older backup, formatting the drive, or
deleting files).
Since joke programs are ordinary executable programs, they will
not infect other programs, nor will they do any damage to the computer
system or its data. Sometimes, joke programs may temporarily reconfigure
the mouse, keyboard, or other devices. However, after a joke program
finishes its execution or the user reboots the machine, the computer
returns to its original state. Joke programs, while normally harmless,
can be costly to an organization.