Ubisoft is recommending that all account holders change their passwords in the wake of recent unauthorized access to its user database.
In a security update posted on the Ubisoft support site, the publisher revealed that unauthorized access to some of its online systems was recently gained through an exploit of one of its websites. That access point was quickly closed but during a follow-up investigation, Ubisoft learned that "data were illegally accessed from our account database, including user names, email addresses and encrypted passwords."
The good news is that Ubisoft doesn't store any payment information on its sites so no credit card numbers were lost, but user accounts are still potentially at risk. Ubisoft didn't specify how many users were affected by the breach but given that it is urging all users to change their passwords, it's a reasonable bet that the number roughly falls somewhere between "we don't know" and "everyone." The company also recommended password changes on sites where the same or similar passwords are being used.
A forum thread has been created to answer any questions you may have regarding the breach, and of course Ubisoft sincerely apologizes for any inconvenience and thanks you for your understanding.