Anonymous, a group of online activists, has attacked a security company that was investigating the collective.
The website of HBGary Federal was defaced with a message from Anonymous, as the group had discovered that HBGary Federal was planning to divulge alleged members of Anonymous to the FBI. In addition, Anonymous downloaded over 60,000 emails from HBGary Federal and posted them on The Pirate Bay file-sharing website, according to security company Sophos.
"You think you've gathered full names and addresses of the 'higher-ups' of Anonymous? You haven't," the group posted on the HBGary Federal website. "You think Anonymous has a founder and various co-founders? False."
The Twitter account of HBGary Federal chief executive Aaron Barr was compromised by hackers, and various private details such as his home address were posted to his Twitter account, said Sophos.
The hackers got into the various HBGary Federal systems through a server that was used for tech support, HBGary Federal co-founder Greg Hoglund said in an interview with security journalist Brian Krebs. The hackers gained access to the emails through a compromised a web server, which also contained Barr's administrator credentials for other accounts.
Anonymous has claimed responsibility for various high profile attacks, including against PayPal, Visa and MasterCard, after the companies refused to process donations payments for whistleblower site Wikileaks. The UK and US police have been involved in an investigation of people who have allegedly been involved in these and other attacks.