There are 4 variants:
When the virus is loaded into memory, it hooks INT 1Ch, 21h to infect any executable that is run or opened by writing itself to the end of the file.
After about 20 minutes of keyboard inactivity, the virus turns the screen into the picture of Grim Reaper's head appears with flashing eyes fades in, then the text "PHANTOM 1" fades in and the skull fades out, then the looping background animation plays and displays the message:
Congradulations!!! Your computer is now infected with a high performance PHANTOM virus! Coming soon: next virii based on the _C00LEST_ mutation engine all over the world: the Advanced Polymorphic Engine! Enjoy this intro! (C) 1994 by Dark Prince.
The keyboard input is then disabled.
This virus has bugs. Sometimes it corrupts the files while infecting: the decryption routine cannot decrypt the virus body. While executing these files halt the system. Second, the video effect does not work under Microsoft Windows and different memory managers.