phpBB.com, the home of the popular open source bulletin board software phpBB has gone offline today due to a hack. The hack was a result of a 0-day-exploit in their PHPList installation which was responsible for sending out release notices. It is important to note that their have been no vulnerabilities found within the phpBB software itself. However, the hacker has gained access to the user accounts stored in the database for the main phpBB forum.
The attacker gained entry through the PHPList application and was able to dump a complete backup of the emails on file. He then used the same exploit to access the phpBB.com database. Both the email list from PHPlist and a copy of the phpBB.com users table were then posted publicly.
For more information regarding the attack, please see this article on the area51 website. If you think you are affected by this hack, you are highly encouraged to start changing your passwords around if you use the same one on more than just the phpBB.com forum.