Mac/nVIR-A first infects the system file and thereafter remains resident in
memory infecting applications as they are executed.
The Macintosh remains infected between restarts. After a preset number of
restarts or after a certain number of applications have been infected
Mac/nVIR-A makes itself known by making the Macintosh beep occasionally when
the computer starts or when an infected application is run. If MacinTalk is
installed then instead of beeping the computer will say "Don't Panic".