This virus infects the same file over and over until it become too large to fit in memory. It traps INT 9 (the keyboard interrupt) and when CTRL-ALT-DEL is pressed it will display the message:
DID YOU EVER DANCE WITH THE DEVIL IN THE WEAK MOONLIGHT ? PRAY FOR YOUR DISKS!! The Joker
Disinfection & Removal
The virus also monitors any keystrokes, activating when 2000 are reached. It will then change the colors of any text displayed on the screen. When 5000 keystrokes are reached the virus will trash the first copy of the FAT.