Rogue NSA sysadmin Edward Snowden says his former employer has developed software that will automatically attack foreign computers deemed to be a threat – without checking in with a human first.

The system, dubbed MonsterMind, is designed to detect strikes against key US servers and block the assaults as quickly as possible. But it is also designed to fire back to take out the perceived attacker without anyone giving it specific authorization.

One would assume American spies had designed MonsterMind to only hack legit targets, but Snowden said incoming salvos on US servers are often routed through other countries, which may fool MonsterMind's targeting systems.

Thus, we're told, a lone miscreant could poke Uncle Sam's computers to trigger a barrage of woe on an unsuspecting nation. This blitzed state may retaliate, leading to all sorts of escalating trouble, Snowden fears.

"These attacks can be spoofed. You could have someone sitting in China, for example, making it appear that one of these attacks is originating in Russia. And then we end up shooting back at a Russian hospital. What happens next?" he asked.

Snowden, an ex-NSA techie, also spoke of the spying agency's vast warehouse of documents, phone calls, emails and other highly personal information, all collected from everyone on the planet.

That data is stored in the NSA's million-square-foot data center in Bluffdale, Utah. Snowden, speaking to WiReD magazine for an article published today, said the center was capable of storing more than a yottabyte of data: a trillion terabytes, in other words.

The building was originally called the Massive Data Repository, but this was changed to the Mission Data Repository since the original name was thought to be too creepy, apparently.

Snowden said it was learning about systems like MonsterMind that helped persuade him that a whistleblower was needed to bring the subject to the American people. But he said the trigger that decided the issue was the Congressional hearings in March last year when the US director of national intelligence James Clapper denied putting US citizens under mass surveillance by "collecting" their online data. That denial has since been challenged.

Youtube video of James Clapper giving evidence

"He saw deceiving the American people as what he does, as his job, as something completely ordinary," Snowden alleged. "And he was right that he wouldn't be punished for it, because he was revealed as having lied under oath and he didn't even get a slap on the wrist for it. It says a lot about the system and a lot about our leaders."

Clapper insists he did not lie to Congress in his statement. Instead, he argues, it depends on your definition of "collect."

Snowden's interview also revealed an interesting snippet on the mysterious outage of Syria's internet access in 2012, which wiped out 92 per cent of the country's links to the outside world. According to Snowden, that disruption wasn't caused by the Syrian government pulling the plug on activists' Twitter feeds: instead it was allegedly caused by the NSA's Tailored Access Operations team, which was trying to install a wiretap on the country's networks.

According to Snowden, the TAO team had an "oh shit" moment when they realized they had bricked a Syrian core router and tried frantically (and fruitlessly) to get it back online to cover their tracks. Time for Plan B.

"If we get caught, we can always point the finger at Israel," one analyst said, Snowden recounts. This is surprising, because if Syria was relying on just one router to connect it to the outside world, it had bigger problems than the NSA.

Leaker's motivation

When Snowden decided to grab a huge cache of documents from his employer, he says he used an automated web crawler looking for key words to troll through the agency's archives. The NSA's internal audits were so lax this wasn't picked up, and to this day Snowden says he believes the NSA has no idea exactly how much data he took.

But Snowden claimed not all of the latest revelations about the NSA have come from him. This supports suppositions by security expert Bruce Schneier and others that there is another NSA mole out there, and possibly more.

Ultimately, Snowden says he is encouraged that the NSA's activities have become of such public interest. But he says it will be technology, not political pressure, that cuts down on state surveillance – echoing similar views from others in the technology industry.

"We have the means and we have the technology to end mass surveillance without any legislative action at all, without any policy changes," he said.

"By basically adopting changes like making encryption a universal standard—where all communications are encrypted by default—we can end mass surveillance not just in the United States but around the world." ®