Well firefox alerts if you try to go to this directly (rather than through google) as this is also considered and attack site, so I don’t know where it gets this list from.
Disabling that part of the security allows direct access and no avast alert, so that isn’t in its malicious sites list.
So in the case of the network shield I doubt even if this was on the list of malicious sites would get involved using the link you gave as a) the domain for the DNS look-up would be google.nl and then it hands off to the secondary URL but it would block that presumably before any DNS request for the IP of webhost4hosting.com.
Good for the newbies here to learn about these things, and good Google action (double)
That is the bonus for going to a certain site through google or scandoo.com and not directly!
When using the google link, I would say that avast did not alert because you never get to the site in order for avast to alert. Google takes you to the warning page first.