As Sony struggles to get PSN back up, new details emerge

With the PlayStation Network expected to be back up within a matter of days, Sony's statements to a US House subcommittee seem to point the finger on responsibility back at hacktivist group Anonymous, which initially denied involvement.

PlayStation chief Kazuo Hirai told Congress in a letter that the company was a victim of a sophisticated attack. As part of the hack, a file was planted on the company's servers named "Anonymous" with the words "We Are Legion." He said the company understood the full scope of the attack by April 25, but could not rule out the compromising of credit card data.

The statement seems somewhat at odds with the company's public statements, which up until at least April 29 seemed to suggest that credit card data had not been touched. Regardless of that fact, Hirai said that Sony had not received any reports of fraud that was believed to be connected to the PSN hack.

Sony's hack is one of several being investigated by the feds, US Attorney General Eric Holder confirmed to Reuters Wednesday.

"I am of course aware of the criticism Sony has received for the time taken to disclose information to our customers," Hirai wrote. "I hope you can appreciate the extraordinary nature of the events the company was facing -- brought on by a criminal hacker whose activity was neither immediately nor easily ascertainable."

Related: AVG Technologies' Tony Anscombe explains how PSN subscribers can protect their identities

Sony apparently feared releasing incomplete information on the attack, so it waited until April 26 -- a week after the actual hack -- to admit a data breach. If it would have been released earlier, it may have led to "confusion and [cause consumers] to take unnecessary actions," it argued.

The identity of those responsible is apparently now known to Sony, and the company told Congress that it was working with law enforcement and the FBI.

Either way, frustrated gamers should not have much longer to wait for PSN to come back up. In a blog post Wednesday, Senior director of coporate communications Patrick Seybold wrote that the company was working "around the clock," and would share details soon on how service would return.

"We will continue to keep you posted as we work to restore our network and provide you with both the entertainment and the security you deserve," he wrote.