shallow - 3:26 pm on Sep 18, 2012 (gmt 0)
You do have to pay closer attention than used to be the case to the installation options if you buy or upgrade something
I always do an "advanced" install to check if there are any addons such as toolbars. I'm really unsure how this one got in. I hadn't installed any programs though did update some firefox extensions and the browser itself which required a new theme.
It's gone now.