BBC News reports an "extremely complex" and "stealthy" spying program has been stealing data from ISPs, energy companies, airlines and research-and-development labs, a security company has said. With a "degree of technical competence rarely seen", Regin had probably taken years to develop, Symantec said. And a nation state may have written it to serve its spying agencies' needs. The program had been used in "systematic spying campaigns" over the past six years, Symantec said. Aimed at Windows users, Regin slowly infiltrated its targets, taking care at each stage to hide its tracks, the company said. "Many components of Regin remain undiscovered and additional functionality and versions may exist," it added.