New documents leaked by Edward Snowden suggest the National Security Agency (NSA) has agents working under deep cover in US and foreign companies.
First published by The Intercept on Friday, the highly-classified document points to the NSA having a small group of well-placed and heavily-vetted insiders, whose mission is to infiltrate commercial companies and work from within.
"How do you know the NSA is not sending people into your data centers?" the publication cited the American Civil Liberties Union's Chris Soghoian as saying.
The collection of six programs, under the umbrella "Sentry Eagle" program, is said to be the "core" part of the NSA's secret mission to "protect America's cyberspace."
In doing that, previous leaks have shown the US intelligence agency will work to weaken encryption standards, intercept technology for bugging once its out for delivery to customers, and conduct network exploitation and espionage.
The NSA has infiltrated a number of companies critical to its mission of targeted exploitation (TATEX). These agents, whose names are not disclosed, are said to be working in companies based in adversarial nations like China, but also allied and friendly countries, notably South Korea and Germany.
Some of the documents also suggest that some agents may be working for US-based firms, or companies that are owned by US corporations.
The 2004-dated document says the contents "constitute a combination of the greatest number of highly sensitive facts related to NSA/CSS's overall cryptologic," referring also to the Central Security Service, the NSA's sister agency.