U.S. government contractor Booz Allen Hamilton confirmed Tuesday that certain of its data files ended up posted on the Internet due to an illegal attack.

"We are conducting a full review of the nature and extent of the attack. At this time, we do not believe that the attack extended beyond data pertaining to a learning management system for a government agency," the McLean, Virginia-based Booz Allen said Tuesday.
On Monday, members of the online activist collective AntiSEc released 90,000 military e-mail addresses and passwords after infiltrating the servers of the military contractor.

The documents were published to torrent-sharing website The Pirate Bay as part of the 'Military Meltdown Monday' campaign of the group, a spinoff from the Anonymous and now-defunct LulzSec hacker teams.

Booz Allen Hamilton provides management and technology consulting services to the U.S. government in the defense, intelligence, and civil markets.

AntiSec noted the lack of security it encountered when trying to infiltrate a server on Booz Allen's network, claiming it "basically had no security measures in place."

AntiSec said last week it had infiltrated the servers of FBI contractor IRC Federal, posting stolen e-mails on both Pastebin and the Pirate Bay.

Booz Allen and IRC Federal works with the U.S. Department of Defense and other federal agencies.

LulzSec, or Lulz Security, hacked the sites of Sony Corp., the CIA, an FBI affiliate, the U.S. Senate, and the Arizona Department of Public Safety, among many others, but disbanded last month after 50 days of high-profile cyber attacks.

Anonymous, an "internet vigilante group," had led a campaign against companies that stopped providing services for WikiLeaks, which released the US diplomatic cables and other sensitive information.