Epic Games has warned customers that their forums have been "compromised by a hacker" and advised users to change their passwords if they are shared with other websites and services.

A notice of the security breach was sent out to users via an e-mail, which states hackers may have "unauthorised access to usernames, email addresses, passwords, and the date of birth provided at registration."

It also details the specific forums that were hacked: "The affected forum site covers UDK,. Powered by Unreal Engine 4, the title will be free to players. The studio has stressed that it is not free-to-play, but will be supported by an in-game marketplace where users can create and sell content.