You’re welcome.

That is the whole point of the avast! Web Shield, it scans content before it arrives (is saved to your system), so the only option on detection is Abort Connection. That file download is dropped so it shouldn’t be on your system, hence no detection on your scan.

Even if this .rar should have been downloaded it wouldn’t present an immediate risk. Archive (zip, rar, etc.) files are by their nature are inert, you need to extract the files and then you have to run them to be a threat. Long before that happens avast’s Standard Shield should have scanned them and before an executable is run that is scanned.