Blizzard Entertainment, the maker of World of Warcraft, Diablo 3, Starcraft, and other widely popular games, has been the target of a network hack. In a lengthy statement on its Web site, the gaming giant confirmed a security breach of its internal network, acknowledging that its security team has spotted "unauthorized and illegal access" into its system. Hackers may have lifted email addresses, answers to security questions, and encrypted passwords linked to player accounts.

"We quickly took steps to close off this access and began working with law enforcement and security experts to investigate what happened," the company explained in its security update. Blizzard added that so far it has not found evidence that sensitive financial data, including gamers' credit card information and billing addresses, had been compromised. "Our investigation is ongoing, but so far nothing suggests that these pieces of information have been accessed."

The hack did, however, lift a list of email addresses for Battle.net users across the world, except those based in China. Battle.net is the overarching account management and login service gamers use in order to play Blizzard games such as World of Warcraft, StarCraft 2 and Diablo 3.

"For players on North American servers (which generally includes players from North America, Latin America, Australia, New Zealand, and Southeast Asia) the answer to the personal security question, and information relating to Mobile and Dial-On Authenticators were also accessed," added the company. "Based on what we currently know, this information alone is NOT enough for anyone to gain access to Battle.net accounts."

The list of passwords used on North American Battle.net accounts was cryptographically scrambled, so even though the attackers got their hands on this list, the passwords are very hard to unscramble, said Blizzard chief Mike Morhaime.

"We use Secure Remote Password protocol (SRP) to protect these passwords, which is designed to make it extremely difficult to extract the actual password, and also means that each password would have to be deciphered individually," explained the company.

Despite this reassurance, Blizzard does recommend that players on North American servers change their passwords as a precautionary measure. To access your account settings and change your password, visit this link. If you used the same or similar passwords for other accounts, consider changing those passwords as well. Users are generally advised to maintain different passwords for each account.

Blizzard also said it plans to automatically prompt its players on North American servers to change their secret questions and answers, in addition to changing their passwords. The company will also warn its mobile authenticator users, who use a phone-based two-factor authentication system to access Battle.net.

"We take the security of your personal information very seriously, and we are truly sorry that this has happened," added Blizzard.