The U.S. has been targeted by a growing cyber espionage campaign from one of its closest allies, South Korea, according to a newly disclosed National Security Agency (NSA) document.
The document was initially published by German news outlet Der Spiegel, and is part of a cache of classified files leaked by former government contractor Edward Snowden.
{mosads}The two countries are long-time allies and closely cooperate on security matters to keep rival North Korea in check.
The partnership between the U.S. and South Korea has also tightened in recent years to curb North Korea’s burgeoning nuclear program and cyber capabilities.
But that hasn’t stopped Seoul from orchestrating a sophisticated cyber spying campaign aimed at the U.S. The discovery of this campaign caused the NSA to up its cyber spying on South Korea in return.
“We aren’t super interested in [South Korea],” said an unnamed NSA employee in the document. “Things changed a bit when they started targeting us a bit more.”
The revelation comes from the same series of documents that showed the U.S. hacked into North Korea’s networks as far back as 2010 to spy on the reclusive East Asian regime.
South Korea is far from the only country spying on the United States. It’s widely believed that China, Russia and likely Iran have all infiltrated U.S. critical networks and are gathering information.
NSA Director Michael Rogers even publicly acknowledged during a December House hearing that China and “one or two” other countries are sitting on U.S. networks.
But the U.S. has a more contentious relationship with China, Russia and Iran than it does with South Korea.
The U.S. has benefited from South Korea’s cyber spying on North Korea and Seoul has profited from the heightened U.S. oversight of Pyongyang.
“We were interested in North Korea and [South Korea] puts a lot of resources against them,” the employee said. “At that point, our access to [North Korea] was next to nothing but we were able to make some inroads,” the employee added, with the U.S. using South Korea’s cyber spying program targeting North Korea.
The North Korean access was crucial in the government’s investigation of the recent cyberattack on Sony Pictures. The access gave the government what it believes was the smoking gun allowing it to blame Pyongyang for ordering the digital assault on Sony.
The attack crippled the film studio’s networks, exposed troves of sensitive data and almost caused the cancellation of a big-budget comedy, “The Interview.”
The government said the hit was North Korean retaliation for the film, which depicted the assassination of its leader, Kim Jong Un.