Interestingly something similar happenned to me a couple of years ago, again with Barclays. But it didn't ask for the maiden name and CVV (as mine was current acccount) but asked for my online pin number (the one previous to pinsentry but which can still be used as if pinsentry doesn't work). It smelt fishy so I checked certificates, padlock, etc, checked AV was ok, and considering this was also on my work computer, I thought it was all legit and carried on.
Got sadly done to the tune of a few £ks despite all that but Barlcays were really good and refunded me. Some transfers had been made to a Polish account. Since then, I've seen similar screens at which point I turn off my pc and reboot, despite all sorts of security stuff running.
I wonder if it's especially Barclays' sites that make it suceptible to hacking.