Gullich is a typical boot sector virus, except that it infects
the DOS boot sectors, not MBRs.
It infects a computer's hard disk only if the computer is
booted with an infected diskette in drive A:, in which case the
virus infects the hard disk's DOS boot sector. The virus goes
resident in memory the next time the computer is booted from the
hard disk. Once in memory, Gullich infects all non-writeprotected
diskettes used in the computer.