Ubisoft's online service has been hacked.
Speaking on the publisher's official forums, a Ubisoft representative confirmed that an exploit found in one of the publisher's websites had allowed "unauthorised access" to "some" of its online systems, resulting in the illegal access of user names, email addresses and passwords.
Ubisoft recommends that all users change their password.
"We recently found that one of our Web sites was exploited to gain unauthorised access to some of our online systems," reads the statement. "We instantly took steps to close off this access, to begin a thorough investigation with relevant authorities, internal and external security experts, and to start restoring the integrity of any compromised systems.
"During this process, we learned that data were illegally accessed from our account database, including user names, email addresses and encrypted passwords. No personal payment information is stored with Ubisoft, meaning your debit/credit card information was safe from this intrusion.
"As a result, we are recommending you to change your password by clicking this link."
Ubisoft also recommends changing your password on any other website or service where you use the same or similar password.
"We sincerely apologise for any inconvenience and thank you for your understanding."
Today's hack marks the second major security alert for Ubisoft in recent months.
Back in April, a security exploit found in the company's Uplay service allowed users to gain unauthorised access to Far Cry 3: Blood Dragon days before the game had been officially announced.