That is odd because it looks like you have to have a login page for it to appear fraudulent. I'm wondering if there was an ad displayed that caused the problem. Have you tried to access that page again?
I think I know what's happening. I've noticed that occasionally there's a banner ad that's "active" -- if you happen to run your cursor over it, it expands into an overlay on the page. I'll bet that when that happens some security software will block it and give an erroneous message. I'm not too impressed with Norton software anyway. I stopped using it several years ago.