Sometime in the past week my PC developed a bit of a pause on quite a few websites, including slashdot.org. At the bottom of the page you can see it trying to connect to the IP address 18.104.22.168 - doing a lookup on that doesn't shed any light.
Googled a couple of threads talking about the same thing
None of the AV checks I ran showed anything up - Malwarebytes, Ad-Aware, Symantec EndPoint and Prevx. IE8 worked ok, just Firefox that is affected (v3.63).
Hosts file is clear.
Also disabled all add-ins and plugins, but it still showed up as a problem.
In the end enabling Adblock Plus in Firefox has stopped it.