The security details of millions of users have been exposed by hackers who attacked Ubisoft, the firm has admitted.
In a statement, the company revealed usernames, email addresses and encrypted passwords have all been accessed illegally in the incident.
Ubisoft has therefore called for all users to change their passwords as soon as possible.
Some 58 million people are thought to have been on its database at the time of attack.
The firm said: "Ubisoft's security teams are exploring all available means to expand and strengthen our security measures in order to better protect our customers. Unfortunately, no company or organisation is completely immune to these kinds of criminal attacks."
Assassin's Creed, Just Dance, Splinter Cell and Far Cry are among the most popular games to have been created by the company in recent years.
Ubisoft's share price dropped slightly today (July 3rd) on the back of the news that it has been a victim of a hack.
Its stocks were trading at 10:38 at 16:09 BST, down 0.38 per cent for the day.
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