Sony Pictures Entertainment confirmed late yesterday evening that some of its websites were breached and it was working with the US Federal Bureau of Investigation to identify the attackers.
Sony Pictures, a unit of Sony, said it had begun an internal investigation into the breach.
On Thursday, a hacker group calling itself LulzSec said it broke into servers that run Sony Pictures Entertainment websites.
The breach is the latest of several security breaches undermining confidence in the company.
The group said it broke into servers that run Sony Pictures Entertainment websites. It published the names, birth dates, addresses, emails, phone numbers and passwords of thousands of people who had entered contests promoted by Sony.
"From a single injection, we accessed EVERYTHING," the hacking group said in a statement. "Why do you put such faith in a company that allows itself to become open to these simple attacks?"
The security breach is the latest attack against high-profile firms, including defence contractor Lockheed Martin and Google Inc.
LulzSec's claims came as Sony executives were trying to reassure US authorities at a hearing on data security in Washington about their efforts to safeguard the company's computer networks, which suffered the biggest security breach in history in April.
Sony has been under fire since hackers accessed personal information on 77 million PlayStation Network and Qriocity accounts, 90 per cent of which are users in North America or Europe.
Sony said at the time that credit card information may have been stolen, sparking lawsuits and casting a shadow over its plans to combine content and hardware products via online services. Nobody has claimed responsibility for the April attack.
Sony said it was investigating the breach claimed by LulzSec and declined to elaborate.
Reuters confirmed the authenticity of the data on several contestants that LulzSec said it had published.
The US Federal Trade Commission could choose to review the circumstances leading up to the breach if Sony Pictures Entertainment failed to use proper procedures for protecting the data of its customers.
John Bumgarner, chief technology officer for the US Cyber Consequences Unit, a nonprofit group that monitors web threats, said he was not surprised that Sony's systems had again been breached.
"The system was unsecure," said Mr Bumgarner, who last month warned of a string of security vulnerabilities across Sony's networks that he had identified. He said he found vulnerabilities in the Sony Pictures Entertainment network as recently as last weekend.
The first hacking attacks in April prompted Sony to shut down its PlayStation Network and other services for close to a month. Representatives criticised Sony in the Congressional hearing for waiting several days to notify customers of the breach.
Reuters
