"There is no information security, there are only varying levels of information insecurity" --Juxo 19:30, 5 Feb 2005 (EET)
Systems security has been breached at an unknown time by an unknown party.
I have no access to any secure system so I can't fix the security. It is known that page content and page histories have been modified directly via MySQL, so basically trust nothing you see currently or in the histories. The index used for searching is one example you can try for yourself searching for Troll song and gets no article matches, search for only song and get plenty of article matches for "Troll song".