Crysis developer Crytek has been forced to take a number of its websites offline following the discovery of “suspicious activity.”

“We recently became aware of suspicious activity relating to some of Crytek’s websites, and acted quickly to take those websites offline for security reasons,” the firm said in an email sent to users.

Crytek.com, Mycryengine.com, Crydev.net, and MyCrysis.com are all currently offline for maintenance. The developer has warned users that they will be requested to reset their password the next time they log in to any of these sites.