"Yes, #NATO was breached. And we have lots of restricted material. With some simple injection. In the next days, wait for interesting data," the group tweeted via the @AnonymousIRC feed.
The group said it "cannot" publish most of the data because that "would be irresponsible." This morning, it did post a link to a restricted NATO PDF, which Anonymous said related to the outsourcing of a communications and information system in Kosovo in 2008, but the doc crashed because of too many connections. Last night, it posted a 2007 document about a similar IT project in Afghanistan.
A NATO spokesman told the Telegraph that it is investigating the claims.
The move comes about two months after NATO called out Anonymous in a draft general report about information and national security. That report noted that "Anonymous is becoming more and more sophisticated and could potentially hack into sensitive government, military, and corporate files."
NATO pointed to Anonymous' February hack of HBGary Federal, which happened days after the firm's then-CEO Aaron Barr told the Financial Times that he knew and planned to expose the identities of leaders behind the Anonymous collective. The subsequent Anonymous attack resulted in the defacing of Barr's online networking profiles and exposure of 71,800 e-mails at AnonLeaks, prompting Barr's resignation.
"It remains to be seen how much time Anonymous has for pursuing such paths," NATO concluded. "The longer these attacks persist the more likely countermeasures will be developed, implemented, the groups will be infiltrated and perpetrators persecuted."
In response, Anonymous said NATO and HBGary Federal were corrupt. "If the government was doing nothing underhand or illegal, there would be nothing 'embarassing' about Wikileaks revelations, nor would there have been any scandal emanating from HBGary," Anonymous said at the time. "Our message is simple: do not lie to the people and you won't have to worry about your lies being exposed."
Anonymous also warned NATO not to "make the mistake of challenging Anonymous."
The organization apparently did not heed that warning in Anonymous' eyes. "Hi NATO. Yes we haz more of your delicious data. You wonder where from? No hints, your turn. You call it war; we laugh at your battleships," Anonymous tweeted later this morning.
This hack comes days after the FBI arrested 16 individuals with alleged links to Anonymous, specifically the cyber attack on PayPal in the wake of the Wikileaks document dump. In an interview with NPR, the FBI said the arrests were intended to send the message that "chaos on the Internet is unacceptable," which did not sit well with Anonymous.
In a separate statement, Anonymous accused the FBI of lying to Americans with fear-based tactics and conspiring with corporations and lobbyists.
"These governments and corporations are our enemy. And we will continue to fight them, with all methods we have at our disposal, and that certainly includes breaking into their websites and exposing their lies," Anonymous said.
Anonymous maintained that officials cannot "arrest an idea."