Harmonix have restored the servers for rockband.com, dancecentral.com and creators.rockband.com after taking them down to investigate an "apparent attack," according to a post by Harmonix developer "hmxhenry" on the official Rock Band forum today.
The creators.rockband.com website will remain down for the short term because of Rock Band Network's "deep integration with multiple third party network services."
"Creators is going to remain down for just a bit longer," the post reads. "Please bear with us as we complete testing to bring it back online."
Last week, the creator of Rock Band and Dance Central warned users via email who have an account with its websites — rockband.com, dancecentral.com and creators.rockband.com — of the attack and placated at the time that "we have not found that any of our users' information has been published or misused."
Account holders are prompted to reset their passwords for the Rock Band and Dance Central sites here and here.