http://www.eicar.org/anti_virus_test_file.htm
Only the https link are detected as threats by web shield. The normal http protocol one isn’t. Just feedback to the developers to improve avast.
I think that your post may be mistaken.
The avast Webshield easily detects the normal http downloads from this site (unless there is something in your configuration preventing the Webshield from working correctly).
avast detects the https downloads on my system not via the Webshield (because nobody and no antivirus can scan SSL secured connections) but because I use a download manager with Firefox that scans all downloaded files using avast.
eicar test is working fine here
Just to chime in here, I used the link provided above,
my no script blocked some scripts, my avast blocked everything else I tried to do.
avast would not allow any of the links to be run, the .com links were blocked, (connection interrupted),
and any of the downloads were detected immediately and properly handled.
I could not reproduce a failure, sorry.