'MusicBug v1.06 MacroSoft Corp.' and '-- Made in Taiwan --'
Like the Azusa virus, this virus infected the computers of a Taiwanese
producer of VGA-driver software, which then distributed infected, shrink
wrapped, write-protected diskettes to unsuspecting users.
When a computer has been infected for four months, the virus enables the
"music" effect. Then it uses the system timer as a random generator to
determine whether it should play a tune or not. The chance of that to
happening is close to 14 percent. The tune it plays is a sequence of
36 notes, each of which is selected at random from a list of eight basic
notes. The authors idea was probably to increase the virus' chances of
spreading, by making it stay silent for the first four months after it
infects a system.
Music Bug infects the DOS Boot sector and also recognises 360K and 1.2MB
5.25" diskettes. It will not attempt to infect 3.5" diskettes.
It assumes the diskettes always have 12-bit FAT entries and hard disks use
16-bit FATs, so it might be quite destructive when this is not the case.
