According to a statement released by Sony's investor relations group, "based on information currently available to Sony, our currently known costs associated with the unauthorized network access are estimated to be approximately 14 billion yen," or about $171 million.
But those costs could go much higher, the company warned investors during a call on Monday. "So far, we have not received any confirmed reports of customer identity theft issues, nor confirmed any misuse of credit cards from the cyber-attack. Those are key variables, and if that changes, the costs could change," said Sony, as reported by Joystiq, which saw a transcript of the call.
Beginning in April, Sony suffered multiple data breaches involving its PlayStation Network (PSN), Qriocity, Sony Online Entertainment, and other sites.
On Sunday, new revelations surfaced that Sony apparently also suffered another data breach earlier this month, after hackers cracked Sony BMG's website in Greece. That would make it the seventh data breach suffered by Sony since April 2011.
In this breach, which occurred on May 5, attackers obtained information about more than 8,000 website users, according to The Hackers News, which received a copy of the website's SQL database from "b4d_vipera," the hacker who took responsibility for the breach.
The attacker also leaked a sample of the purloined database--containing 450 records--to Pastebin. It contains usernames, passwords for the Sony website, and email addresses. Security experts recommend that anyone with a Sony BMG account in Greece immediately change their Sony password, and any other uses of the same password online.
The attacker said he exploited the Greek Sony website using a SQL injection attack against the site, which was running Internet Information Server (IIS) 6.0 on Windows 2003. SQL injection attacks, which exploit website databases that haven't been patched against known vulnerabilities, are much favored by attackers, in part for their simplicity.
"It's not something that requires a particularly skillful attacker, but simply the diligence to comb through Sony website after website until a security flaw is found," said Chester Wisniewski, a senior security advisor at Sophos Canada, in a blog post.
In the wake of numerous data breaches involving more than 100 million user accounts, Sony is still attempting to get its systems fully secured and back online. Some of its Web properties, such as PlayStation Store, remain offline.
On Wednesday, Sony also deactivated online password resets for PSN and Qriocity, saying its password system couldn't handle the load.
But rumors that the password reset site had been compromised by attackers weren't true, said Patrick Seybold, Sony's senior director of corporate communications and social media, in a blog post. "Contrary to some reports, there was no hack involved. In the process of resetting of passwords there was a URL exploit that we have subsequently fixed."
While Sony works to get its online password-reset process reestablished, Seybold said that PSN users can reset their passwords via their PlayStation 3. "Otherwise, they can continue to do so via the website as soon as we bring that site back up," he said.
In this new Tech Center report, we profile five database breaches--and extract the lessons to be learned from each. Plus: A rundown of six technologies to reduce your risk. Download it here (registration required).