Sony: Hacking of PlayStation Network was a "highly sophisticated" attack

According to The Wall Street Journal, Sony has sent a letter to members of the United States Congress today. The topic of the message was the recent hacking of the PlayStation Network, which caused more than two weeks of downtime for PlayStation users. In the attack, names, addresses, email addresses, usernames, passwords, and maybe even credit card information, was all exposed. The hack is now being called the “biggest-ever data breach” and the hackers appear to have removed all traces of the attack.

Sony, in a letter to members of Congress released Wednesday, said the hacker or hackers deleted any traces of their attack, which is regarded as one of the biggest-ever data breaches. In the course of its investigation, however, Sony said it discovered a file left on its servers called “Anonymous.” The contents of that file said “We are Legion,” which is the tagline of a loosely federated group of Internet vigilantes dubbed Anonymous, Sony said.

Sony said it had been defending itself from attacks that sought to disrupt its websites at the time that intruders stole customers' personal information from its servers. Anonymous had previously said it would attack the company in retaliation for a lawsuit the company brought against a popular hacker, George Hotz.

Sony said in the letter that it is investing the criminal attack with the Federal Bureau of Investigation (FBI) and is attempting to track down the hackers.

Also in the letter, Sony claims that it is the “victim of a very carefully planned, very professional, highly sophisticated criminal cyber attack designed to steal personal and credit card information for illegal purposes.”

Finally, Sony confirmed that roughly 77 million PlayStation Network accounts were affected by the breach, with an additional 24 million in a Sony Entertainment Online attack that occurred this week as well.