%%File: VIRS0102.TXT
%%Name/Aliases: 512, 512-A, 512-B, 512-C, 512-D
%%Platform: PC/MS-DOS
%%Type: Program., 
%%Disk Location: COM application.
%%Features: Memory resident; TSR.
%%Damage: 
%%Size: 
%%See Also: 
%%Notes: The virus hides in the first 512 bytes of free space in the 
last cluster of a .COM file.
When RAM-Resident, it hides in the disk buffer space for code in order 
not to take-up memory.
Files do not appear to change in length, because the virus removes 
itself on the fly when the file is accessed by another program.

virus-l, v4-131 says that a variant of the 512 and Doom-II virus can put 
executable code into video
memory.     "666" at offset 509.   A Do-it-yourself way: Infect system 
by running an  infected file, ARC/ZIP/LHARC/ZOO all infected COM  and 
EXE files, boot from uninfected floppy, and UNARC/UNZIP/LHARC E etc. all 
files. Pay special attention to disinfection of COMMAND.COM.