Sony Corp. said Tuesday that names, birth dates and possibly credit card numbers of its 77 million PlayStation Network gamers may have been accessed in a hacker attack.

In a blog post on its U.S. website for PlayStation division, Sony disclosed that between April 17 and April 19, certain PlayStation Network and Qriocity service user account information "was compromised in connection with an illegal and unauthorized intrusion."

PlayStation Network is Sony's online service for use with its PlayStation video game consoles. Qriocity is an entertainment service platform that connects many of Sony's network-enabled devices.

Sony believed that the hacker has obtained names, addresses, birth dates, login and other information that the two services' registered account holders provided.

It is also possible that the intruder might have obtained users' data including purchase history and billing address, Sony said.

"While there is no evidence at this time that credit card data was taken, we cannot rule out the possibility," it noted in the blog post.

Sony warned that users should closely monitor their credit reports and "be especially aware of email, telephone, and postal mail scams that ask for personal or sensitive information."

Sony has asked an outside security firm to investigate the incident, saying that PlayStation Network and Qriocity services, temporarily turned off after the intrusion, are expected to be partially restored within a week.

VietNamNet/Xinhuanet