These are not dangerous memory resident parasitic viruses. They hook INT 1, 3, 9, then they trace INT 21h and patch the first byte of DOS part of INT 21h handler with CCh opcode (INT 3 call). On execution of COM and EXE files thise viruses write themselves to the end of these files. Sometimes they change the letters on the screen:
from to
----------
:-) :-(
:=) :=(
;) ;(
|) |(
These viruses contain the text:
Shiny Happy Virus by Hellraiser and Dark Angel of Phalcon/Skism
