NSA, GCHQ used open source software to spy on Israeli, Syrian drones

Documents provided to The Intercept by National Security Agency whistleblower Edward Snowden show new evidence of a long-running surveillance campaign against drones flown by the Israelis, Syrians, and other nations in the region. The operation by the United Kingdom's Government Communications Headquarters (GCHQ) signals intelligence organization, with the assistance of the NSA, intercepted scrambled analog video feeds from remotely piloted aircraft and tracked the movement of drones. In some cases, the operation even intercepted video from Israeli fighter aircraft during combat missions.

There was no supercomputing magic involved in at least most of the video interceptions. As part of an operation codenamed "Anarchist," NSA and GCHQ analysts used Image Magick (an open-source image manipulation tool) and other open-source software developed to defeat commercial satellite signal encryption. One of the tools, called antisky, was developed by Dr. Markus Kuhn of the University of Cambridge's Computer Laboratory. The tools could be used by anyone able to intercept satellite signal feeds then exhibit the patience and skill to sort through the pixels. However, the conversion to digital video feeds on some drones has apparently made video interception more difficult.

The signals were intercepted at a GCHQ station at the Royal Air Force's communications installation in the Troodos mountains of Cyprus. The facility, near Mount Olympus, is used by the GCHQ for exploiting satellite and radio communications in the eastern Mediterranean and Levant regions—including Israel, Syria, Lebanon, Turkey, Egypt, and much of North Africa. The encrypted signals were then processed with Image Magick and antisky, according to a training manual obtained by The Intercept. That manual details the process of "brute forcing" the breaking of encryption on satellite video feeds.