Ubisoft has initiated a company-wide password reset after it detected a "cyber security incident" last week.
The publisher of Assassin's Creed, Far Cry and Rainbow Six said the incident had caused disruption to its services, including certain games.
While these have now returned to normal, the matter remains under investigation.
Importantly, Ubisoft stressed there was no suggestion at this point that any user information had been exposed.
Here's Ubisoft's statement in full:
"Last week, Ubisoft experienced a cyber security incident that caused temporary disruption to some of our games, systems, and services. Our IT teams are working with leading external experts to investigate the issue. As a precautionary measure we initiated a company-wide password reset.
"Also, we can confirm that all our games and services are functioning normally and that at this time there is no evidence any player personal information was accessed or exposed as a by-product of this incident."