Parity_Boot.B infects the boot records of diskettes and the
Master Boot Records of hard disks. As a typical boot sector
virus, Parity_Boot.B can infect hard disks only during a
diskette boot. The virus reserves one kilobyte of
conventional memory for itself and infects all non-write-
protected diskettes used in an infected computer.
Parity_Boot.B uses stealth techniques, so the changes the
virus has made cannot be detected while it is active in
memory. Parity_Boot.B activates at random times and prints
the message "PARITY CHECK" on the screen. After this, the
virus crashes the computer, simulating a genuine error
situation due to faulty memory circuits.
Incidents involving the Parity_Boot.B virus have lately
popped up in several parts of the world. The virus seems to
be especially common in Germany, probably because the virus
infected a cover-disk distributed by one of the biggest German
computer magazines in late 1994.
[Analysis: Mikko Hypponen, F-Secure]