AntiExe is a simple boot sector virus, infecting floppy boot
records and hard disk master boot records. The virus is very
small and it is not encrypted.
AntiEXE uses stealth techniques, so infected boot sectors look
clean if inspected while the virus is resident. F-Secure
anti-virus products will detect if AntiExe is resident, and will
advise you to boot from a clean diskette.
The virus will only infect hard drives when an attempt to
boot from an infected diskette is made. Once the virus has
infected the hard drive, all non-write-protected floppies used
in the machine will be infected.
AntiExe virus redirects the BIOS disk interrupt 13h to unused
interrupt D3h - this way the virus can bypass some behaviour
AntiEXE targets an unknown EXE file, sized 200768 bytes
(memory size 200256 bytes). Whenever this specific EXE file
is accessed, the virus prevents it from running.
AntiExe is very common all over the world.
[Analysis: Mikko Hypponen, F-Secure;
thanks to S. Widlake for pointing out an error in the description
and Alan Candy for providing additional details]