Some time during the last week I guess there's been a definitions update that has caused Avast to delete scalc.exe, which is the OpenOffice 4.0.1 spreadsheet program launcher. I've been away for most of last week, so can't be more precise when this started happening, but it did it on 29 May as soon as I got back. My scalc.exe is now in the virus chest, and the reported virus is "FileRepMalware".
scalc.exe has been on my machine since September 2013 without causing any apparent problems, so I hope this is a FP which can be fixed soon. scalc.exe won't work outside its home directory, so I can't restore it to a temp directory somewhere and exclude that. I don't want to have to exclude the whole of the OpenOffice program directory from Avast scans, for obvious reasons.
I'm using Avast free edition, which declares itself fully up to date: prog version 2015.10.2.2218, definitions version 150530-0. Windows 7 64-bit Pro.