Gullich is a typical boot sector virus, except that it infects the DOS boot sectors, not MBRs.
Allow F-Secure Anti-Virus to disinfect the relevant files.
For more general information on disinfection, please see Removal Instructions.
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.