Frequent attacks suddenly

I am running a fully updated version of Windows 7 Professional as is all the other software on my system (Norton Security of course, Adobe, Adobe Flash, Java, Apple software etc.). Last night Norton Security warning me that a lot of data is being uploaded and prompts me to run Norton Power Eraser. Then shortly after that Norton indicated it blocked an attack (last night it was "Web attack: Magnitude Exploit Kit Website 2"). I ran Norton Power Eraser and no risks were found, I did a full system virus scan and no threats were found.

Now today I've experienced a number of attacks again in Norton History, all blocked by Norton Security. The "High" risk threats were: "an intrusion attempt by 31.184.194.100 was blocked - web attack: MSIE XMLDG M Active X CVE-2013-7331", and "an intrusion attempt by 31.184.194.37 was blocked - system infected: Trojan.Ad Clicker Activity" , and "an intrusion attempt was blocked - system infected Trojan.Pro Welik Activity". 

In all cases Norton Security indicates "No Action Required".

At the times of these attacked I was surfing (using Internet Explorer 11) news sites i.e. New York Times, Fox News, CNN, MSN etc., and a couple shopping sites like Amazon, L.L. Bean etc., nothing I would believe to be high risk. Is anyone else experiencing a spike in this kind of activity? Is Norton Security covering all the bases on this?

Thanks, Rick