Ok so in the last 2 days, i've gotten the same error when attempting to log-in to wow.
First time, after getting a critical error and not being able to login again without getting that same error, I come to find out I have a keylogger. I updated my Malwarebytes, run it and get everything cleaned up. This was 2 days ago, at around 11PM Christmas Day.
Now today, I closed wow down, went to curse to download a few addons and had the curse client install them. I go to login to wow, exact same error as before. Only sites I've been on since waking up is Facebook, MMO and Curse.