"This week, our security team found an unauthorized and illegal access into our internal network here at Blizzard. We quickly took steps to close off this access and began working with law enforcement and security experts to investigate what happened," said Blizzard president and co-founder Mike Morhaime in an "important security update" posted late Thursday to the site.
While Blizzard's investigation is still continuing, "at this time, we've found no evidence that financial information such as credit cards, billing addresses, or real names were compromised," he said. "We deeply regret the inconvenience to all of you."
Information obtained by attackers included a list of all Battle.net players, except for those in China. Meanwhile, for players based on the North American Battle.net servers, which the company said "generally includes players from North America, Latin America, Australia, New Zealand, and Southeast Asia," attackers also accessed players' personal security--or secret--questions, as well as mobile and dial-in authentication information. "Based on what we currently know, this information alone is not enough for anyone to gain access to Battle.net accounts," said Morhaime, though he said the Battle.net site will soon prompt all users to update their secret questions and answers, and require mobile authenticator users to download new authenticator software.
[ Keep your identity safe. See 8 Ways To Avoid Getting Your Life Hacked. ]
Attackers also obtained copies of North American server players' passwords, raising the possibility that they'd be able to access people's accounts. Thankfully, unlike numerous other recent breaches, those passwords were encrypted, in this case using Secure Remote Password (SRP) protocol, "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," said Morhaime. "As a precaution, however, we recommend that players on North American servers change their password." He also urged anyone who'd reused the same or similar password on another site to change it in all places.
Thankfully, SRP will slow down anyone who wants to decrypt the stolen password list, which would seem to buy Blizzard players some breathing room. On the other hand, Blizzard has yet to confirm exactly when attackers breached its systems--and may not yet know for certain--meaning that the attackers may have already had time to decrypt some of the stolen passwords and begin putting them to use.
Why make a grab for Battle.net player information? The most likely explanation is for harvesting email addresses for use in phishing attacks, and Blizzard warned all players that they should never access the site or share any information via any email they receive. "As a reminder, phishing emails will ask you for password or login information. Blizzard Entertainment emails will never ask for your password," said Morhaime.
Attackers may also have plans to convert the virtual items acquired by various players into cash. With the debut of Diablo III earlier this year, Blizzard also created a Battle.net auction house that allows players to buy and sell in-game items for real money. But third-party sites have also long offered players the ability to buy and sell virtual items for cash.
Will the security breach cost Blizzard customers? Activision Blizzard reported $4.8 billion in 2011 revenue, and much of that is due to Battle.net and its signature massively multiplayer online game (MMOG) World of Warcraft, a.k.a. WoW.
Last week, Blizzard reported that its World of Warcraft subscription base dipped to 9.1 million users, after having peaked at 12 million in 2010. Despite criticism that the seven-year-old MMOG is fading, it's still the company's golden goose, and massively profitable. Subscription fees for the game are $15 per month, or $78 for six months. While some players use a free trial version of the game software, that still means Blizzard likely sees well over half a billion dollars per year in revenue just from World of Warcraft subscriptions.