It is a dangerous memory resident parasitic virus. When executed it copies itself into the system memory, and does not fix MCB list, that might cause system confusion. Then it hooks INT 21h and on several DOS calls it searches for .COM files of the current directory and writes itself to the end of the file. Depending on the system timer the virus decrypts and displays one of the messages:
You have the Joker ]I[ virus by Crypt Keeper [Joker 3]
Please insert tractor-feed toilet paper into printer
Impotence error causing erection at port adress 3E2 IRQ 5
This program requires Microsoft Windows.
Computer hungry : Insert 5-1/4 inch HAMBURGER in drive A:
Missing Light Magenta/Olive ribbon in printer.
Not enough memory.
Packed file corrupt.
Bad command or file name
Bad or missing command interpreter.
