Updated July 6th, 2015: After thorough investigation by a team of forensic specialists, we’ve identified the source of the compromise to the forums server. As we had suspected, the attackers gained entry via exploiting bugs in the forums software, some of which may not be well understood or publicly disclosed, or have patches readily available. The investigation did not turn up any other compromised systems.
We’re continuing to investigate, but as you can imagine, it wouldn’t be wise to bring the forums back to life before being comfortable that we’re not vulnerable to the same attack. As such, we’re exploring all options, including migrating to new forums software.
We’re committed to bringing back the forums as soon as humanly possible. We worked tirelessly over the holiday weekend, and will continue to work until the forums are back. We appreciate your continued patience, and apologize for this inconvenience.