Hi NON,
In order to understand what's going on, it's important to realize that the Web Shield in Avast Mobile Security can only check the URLs you visit, not the actual content. This is because of the technical limitation of the Android platform, and is how all other security products work as well.
As there are no (or very very few) web-based attacks for the Android platform at the moment, the main goal of our Web Shield is to protect against phishing sites.
True, we could have also blocked the eicar URLs (on eicar.com / eicar.org) but we'd find this a bit lame (doing that just for the sake of passing those "tests"...).
Hope this helps,
Vlk