WASHINGTON (Reuters) - Documents leaked by Edward Snowden show that the US government has widened the National Security Agency's warrantless surveillance of Americans' international Internet traffic in the hunt for hackers, the New York Times reported on Thursday.
The classified documents came from Snowden, the former NSA contractor who lives as a fugitive in Russia, and were shared with the Times and the investigative journalism non-profit ProPublica, the newspaper reported.
In mid-2012, Justice Department lawyers wrote two secret memos allowing the NSA to begin hunting on Internet cables, without a warrant and inside the United States, for data linked to computer intrusions originating abroad, the Times reported, citing the documents. It said the data included traffic that flows to suspicious Internet addresses or contains malware.
The disclosure of the documents come as US financial institutions, businesses and government agencies are increasingly being targeted in cyberattacks, the Times noted.
The Times reported that the Justice Department permitted the NSA to monitor only addresses and "cybersignatures," patterns tied to computer intrusions, that it could link to foreign governments. But the documents showed that the spy agency sought to target hackers even when it could not establish links to foreign countries.
During a briefing, White House spokesman Josh Earnest said he was "not in a position to talk in a lot of detail about any sort of covert government programs that may or may not exist." But he said President Barack Obama's administration will remain vigilant about an "ever-evolving" cyber-threat that is increasing in frequency, scale, sophistication and severity.
Brian Hale, spokesman for the Office of the Director of National Intelligence, was quoted by the Times as saying, "It should come as no surprise that the US government gathers intelligence on foreign powers that attempt to penetrate US networks and steal the private information of US citizens and companies."
Hale also was quoted as saying that "targeting overseas individuals engaging in hostile cyberactivities on behalf of a foreign power is a lawful foreign intelligence purpose."