The Ubuntu forum has been taken offline following a data breach that saw cyber criminals make off with users' account and email information.
Ubuntu confirmed the forum, which has over 1.8 million accounts registered to it, was breached but promised the user passwords are still encrypted, so the hackers should not be able to use them. "Unfortunately the attackers have gotten every user's local username, password, and email address from the Ubuntu Forums database," said the Ubuntu Forums statement.
"The passwords are not stored in plain text, they are stored as salted hashes. However, if you were using the same password as your Ubuntu Forums one on another service, such as email, you are strongly encouraged to change the password on the other service ASAP."
Ubuntu said it is working to plug the breach and get the forum back online as soon as possible, confirming that none of its other services were affected.
"There has been a security breach on the Ubuntu Forums. The Canonical IS team is working hard as we speak to restore normal operations. This page will be updated regularly with progress reports," read the statement. "Ubuntu One, Launchpad and other Ubuntu/Canonical services are not affected by the breach."
Security expert Graham Cluley noted that the emails could be used to launch phishing attacks. "Of course, compromised passwords leading to account hacking aren't the only risk here. There is also the danger that the hackers could use the email addresses they have stolen for spam campaign, perhaps even launching a carefully crafted attack designed to pique the interest of Ubuntu lovers," wrote Cluley.
Ubuntu's forum is one of many to be targeted by hackers. The NASDAQ Community forum was also recently hit with a similar password-stealing attack.