Haven't heard of a virus since the one that came out in 1998, but I suppose
it's possible (see http://www.fmsinc.com/free/utilities/fmsavs10.htm for
details about that one)
Are you sure that something isn't preventing the LDB files from getting
deleted, though? That would make Access think that the database is open.

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Doug Steele, Microsoft Access MVP
http://I.Am/DougSteele
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> Has anybody encountered a virus that attacks .mdb files
> making them un-openable? Virus scans haven't showed
> anything, but the files show that they are already open,
> but not by me!
Check to see if you have any Access Processes still running; maybe it
didn't close down properly last time.
also check if the locking file is present.
First thing I would suggest of course is clean re-boot. Can you tell I
have worked in support.... :o)