User blog comment:TheAzumangaDaiohFan/What Happened with The RIPWiki Redirect Glitch? 10/4/15/@comment-25428589-20151005054849

If anyone's interested in how this happened:

A utility account used by Wikia staff for Quality Assurance was compromised (I believe this may have been done through simply guessing the password, as I've been told by staff they have no reason to believe there are any open attack vectors through which this could have been done). From there, the attacker was able to access the Wiki Factory (a MediaWiki extension that allows staff to manage the entirety of Wikia) and close/redirect wikis via that.