It is a very dangerous memory resident parasitic virus. It hooks INT 21h and writes itself to the end of .COM and .EXE files that are executed or opened. Starting from 2000, on March 5th the virus overwrites the MBR and the first boot sector of the hard drive with a trojan program that decrypts and displays while booting:
Internal Error
The virus also contains the encrypted text:
Virus FANTASMA. Mexico 1996
