Virus.DOS.BGU or BGU is a virus that runs on MS-DOS.
BGU is not dangerous memory resident parasitic viruses. It hooks INT 21h, 28h and write itself to the end of COM and EXE files that are accessed. Some time after installation this virus displays the white-red-white flag (old Belorussian flag) and beeps with PC speaker. On old XT this beep sounds as a melody. The virus contain the text string:
Securelist (Kaspersky Labs), Virus.DOS.BGU.1298