Don't worry too much about that detection, yet.
Best to do one thing at a time. No need to keep doing thorough scans with Avast, until we have determined what is at play, and is it still at play, and what needs to be done with it.
It is quite possible it was a temporary file created by SAS, that contains information resembling malware, without being malware itself.
(Or maybe not.)
Now. Why can't you read the SAS logfile? Is it in some kind of code, like crypted? (Sample below, if it attaches/displays correctly.)
It should be a simple text file that opens in notepad, if it's not, please advise, also advise the full path and file name, including the suffix.
Attaching it should be a simple process using the "additional options" button to the lower left of the forum reply window. It is size limited, but a scan log should not exceed that limit.
If you don't want to faff around downloading Ccleaner, try
ATF Cleaner, from MajorGeeks, by
Atribune. (I include the second link just so you can, if you want, check the pedigree of the program.)
This one is downloaded by clicking on one of the links immediately below the animated "downloads" chevron. It will run from the download location - might as well save it to your desktop. When it is opened, tick the boxes as per my picture, click on "empty selected", it will take a few seconds then let you know how much space has been freed.
What we are doing should not hurt your computer. If there is malware present, that could be doing some harm, which is what I'm trying to find out, and if possible fix.
Once we are at a certain point, I'll ask for help from one of the forums malware experts, because there are a few here who know a bit more about it than yours truly! But I know enough to be helping you through these stages.
