Konami has become the latest gaming firm to be hit by a cyber attack after more than 35,000 online customer accounts were potentially compromised.
Earlier this week, the publisher detected 35,252 cases of unauthorised logins to its Konami ID site from just under four million attempts between June 13 and July 7.
The publisher said in a statement that the unauthorised logins were made using IDs and passwords "that appear to have been leaked from an external service provider".
Customer information that may have been exposed includes names, addresses, dates of birth, telephone numbers and email address.
"No changes to customers' personal information, or unauthorised usage of paid services, have been detected," Konami said.
The company advised users to change their passwords and said it was in the process of contacting affected customers individually via email.
"Konami sincerely apologizes for the trouble this has caused to our valued customers... Konami has strengthened its security and raised its monitoring level, and measures have been taken to ensure that IDs and passwords involved in these unauthorized logins can no longer be used to log in."
On July 5, Nintendo confirmed that hackers had managed to break into the Club Nintendo website on more than 23,000 occasions in the previous month.
And earlier today, Arma studio Bohemia Interactive said hackers had withdrawn personal information from its user database.