Hmm. It seems to be a random thing, because after I rebooted Avast and the Network Shield, I can now visit websites normally. It looked like a regular Avast virus alert(red window in the bottom right) and it said "Malicious Website Blocked". Under that it said the IP of the website, the URL, and the process(iexplorer.exe). There was a link in the bottom of the window that said "More Info", and when I clicked on it, it sent me to a webpage that said something like "That was a close call, but upgrade to Avast! Security Suite now and you won't have to worry about this again!" then told me all about the savings on the paid version. The More Info link gave me no info on why the site was blocked, just advertisements for the paid version. If it happens again, I'll take screenshots and post them here, in this thread or a new one.