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.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
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.
Description Created: Mikko Hypponen, F-Secure