'Network was hacked in possible blackmail'

Sony Corp. (SNE)'s computer network was hacked in what may be a blackmail attempt, according to a person with knowledge of the matter.

The breach of the entertainment and electronics company's systems is under investigation, said the person, who wasn't authorized to speak publicly and asked not to be named. In a statement, Sony said it was investigating "an IT matter."

The incident began when a picture of a skull appeared on company computer screens, the entertainment website Deadline.com reported yesterday.

The image was accompanied by a message that read Sony had been hacked by #GOP and that private data would be released at 6 p.m. New York time yesterday if its undisclosed demands weren't met.

The hack is being linked to a group called "Guardians of Peace," the person said. Sony declined to comment beyond its statement. Many large global companies have fallen prey to computer hackers. JPMorgan Chase & Co, Home Depot Inc. and Target Corp. have all been subject to hacks.

In the case of JPMorgan, hackers earlier this year accessed data on 76 million households and 7 million small businesses. This month, Home Depot said 53 million e-mail addresses were taken, in addition to the 56 million payment cards that were previously disclosed.

PlayStation Network and Sony Entertainment Network, which enable gamers to play each other and access content, were taken off line by a so-called distributed denial of service attack, the Tokyo-based company said in August. At the time, the company said it had no evidence that personal information was accessed by computer hackers who drove artificially high traffic to Sony servers, it said.

Sony American depositary receipts rose 1.8 per cent to $21.63 at the close in New York yesterday. They have gained 25 per cent this year.