Hacker group Anonymous on Monday released a trove of military email addresses and passwords it claimed to have plundered from the network of US defense consulting firm Booz Allen Hamilton.
Anonymous made available a file containing more than 90,000 email addresses and other information it said in online messages that it stole from an unprotected server at Booz Allen.
"In addition to the emails, Anonymous claims to have erased four gigabytes worth of source code and to have discovered information which could help them attack US government and other contractors' systems," computer security firm Sophos said in a blog post.
"While this should certainly be embarrassing to Booz Allen Hamilton, the real impact is on the US military," the post continued.
In a message accompanying the data at file-sharing website The Pirate Bay, Anonymous said Booz Allen was targeted in a "Meltdown Monday" as part of an anti-security, or "antisec," movement.
"So in this line or work you'd expect them to sail the seven proxseas with a state-of-the-art battleship, right?" Anonymous said using teasing pirate jargon and playing off a reference to proxy computer servers.
"Well, you may be as surprised as we were when we found their vessel being a puny wooden barge," the message continued. "We infiltrated a server in their network that basically had no security measures in place."
While some downplayed the value of the looted data, computer security specialists warn that the email addresses could be used to target messages that trick recipients into revealing information or downloading viruses.
Booz Allen responded to an AFP inquiry by saying "we generally do not comment on specific threats or actions taken against our systems" as per a company security policy.