All of them belonged to some Adobe programs, and were reported to be located in C://System Volume Information/_restore/several letters and numbers.exe.
As far as I know I don't have any password-protected folder, and I can't find any System Volume Information folder.
A Search came up with nothing. I have had nothing like this on Friday, and days before, for years. I don't scan on Saturday. I may have update Adobe Reader, on Friday, but there is nothing strange in the Adobe Folder.
Before going to the Avast forum, does this ring any bell?