I was in the process of closing Skyrim and I noticed on my Network Shield (open on my second monitor) a blue benign spike for hwcdn.net. I never ever saw anything from this site before. I was wondering if I should be concerned?
Sites that you visit and also links to 3rd party sites, the Network Shield checks the site against its malicious sites list to ensure that they aren't malicious. The only ones that would concern you are if avast alerts, otherwise this is showing that the site isn't on its malicious sites list.
Don't forget the web shield is also active looking for malicious content, not just is a site is on the network shield malicious sites list.