Wikipedia: The Joint Threat Research Intelligence Group (JTRIG) is a unit of the Government Communications Headquarters (GCHQ), the British intelligence agency . The existence of JTRIG was revealed as part of the global surveillance disclosures by NBC News in documents leaked by the former National Security Agency contractor Edward Snowden.
Edward Snowden released this top secret document, and Glen Greenwald published it on his website The Intercept. Hat tip to Glenn Greenwald and Edward Snowden.
JTRIG – Joint Threat Research Intelligence Group