Ok, not so much hacked as social engineered... UGNazi has claimed credit, same clowns as WHMCS last week (of which I use). They did leak the entire site last time... Oh, who is next....
I never understand how anyone can give out any credentials to anyone. Too bad for them that they have stupid people in charge of the servers.
To our knowledge, they never actually managed to get access to the servers, just the domains. It was the result of a compromise of Chris' Apple ID (and we're not entirely sure how they managed to get access it), but they were able to reset passwords for the hosting and domain that way. Fortunately SoftLayer called Chris directly when the hosting password was reset and were able to completely shut off public access to the server shortly afterward. A full explanation of what happened can be found here: http://blog.mybb.com/2012/06/02/well-be-back-soon/
It's a very odd attack vector. So unfortunate that MyBB was targeted as a result of one of their users forums.
Yeah nothing to do with the myBB software and everything is sorted now so there is no issue in using the myBB software.