In a statement released Thursday, the group claimed that it had also managed to compromise all "admin details," including administrator passwords, as well as 75,000 "music codes" and 3.5 million "music coupons" from Sony networks and websites.
The group has publicly posted a full list of compromised sites, along with links to documents containing samples of what it claimed was material stolen from Sony.
The compromised databases included one that appeared to contain information belonging to people who participated in a promotional campaign involving Sony Pictures and AutoTrader.com, as well as another involving a Sony-sponsored Summer of Restless Beauty campaign.
Also compromised in the break-in, according to LulzSec, was a Sony music codes database, a music coupons database, and databases from Sony BMG Belgium & Netherlands.
The compromised databases contained "varied assortments of Sony user and staffer information," the group said.
"SonyPictures.com was owned by a very simple SQL injection, one of the most primitive and common vulnerabilities, as we should all know by now," LulzSec said. "From a single injection, we accessed EVERYTHING."
"What's worse is that every bit of data we took wasn't encrypted," the group claims. "Sony stored over 1,000,000 passwords of its customers in plaintext, which means it's just a matter of taking it."
LulzSec said that it had copied and published only a relatively small sample of the information it had managed to access because it did not have the resources to download everything. The group said that in theory it could have "taken every last bit of information," but that would have taken weeks.
The group posted a link to the SQL injection vulnerability it had exploited and invited anyone to verify it personally. "You may even want to plunder those 3.5 million coupons while you can."
In response to a request for comment, a Sony spokeswoman said the company would send a statement by email to Computerworld, but has not yet done so.
If the breach is as extensive as LulzSec has claimed, it would be the second major compromise that Sony has suffered since mid-April, when intruders broke into its .
Those breaches resulted in the compromise of personal data belonging to nearly 100 million account holders.
Since then, there have been a at various .
The attacks, such as the one carried out against Sony Pictures by LulzSec, have been designed largely to embarrass Sony, which has sparked the wrath of many hackers for its hard line stance over copyright and IP protection.
The continuing attacks have become a huge issue for the company. Sony was forced to shut down its PlayStation Network and Sony Online Entertainment networks for several days to fix issues resulting from those intrusions. Even now the networks are .
So far, Sony has hired at least three external firms to help patch its networks. It also recently hired a new chief information security officer to help coordinate its security efforts. With the company's websites having been routinely broken into, despite such measures, many wonder just how porous Sony's networks are.
Sony itself characterized the PlayStation Network and Sony Online Entertainment intrusions as highly targeted and sophisticated cyberattacks. However, all of the publicly disclosed ones since then appear to have been the result of some fundamental security oversights on the part of the company.
Several of the attacks have resulted from SQL injection flaws that hackers have claimed were extremely easy to find and to exploit.
Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at or subscribe to . His e-mail address is .
in Computerworld's Network Security Topic Center.