Symantec just started putting this new file into that folder.

This file appears on every updated SAVCE 10.x client I check at
C:Program FilesCommon FilesSymantec SharedVirusDefs.

It began appearing today 8-26-2009   (or possibly yesterday 8-25 but I was out then). 

It does not look like malware but I submitted it for analysis.

Symantec is putting it there. Tested this sequence:
Found a client that needed help updating.  It had NO Cat .db file there.
Pushed a def update to it.
Lulock.dat appears.
Later The update is complete and a CAT.db file is now in the above path in the VirusDefs folder.

Thanks