These are not dangerous memory resident parasitic viruses. They copy themselves into Upper Memory Blocks, hook INT 21h, then they write themselves to the end of EXE files that are executed. Depending on the system timer these viruses display one of the messages:
FIRE FIRE FIRE!
Hey butthead this sucks change the channel!
Shut up butthead or I'll kick your ass!
We're there dude.
The Beavis virus kicks ass!
The viruses also contain the text strings:
"Beavis.655,657": [BEAVIS]
"Beavis.671,673": [BEAVIS] by Crypt Keeper
