There are many things that one can say about America's premier spy agency, the NSA, but one can never accuse it of not instilling an incredible degree of loyalty among most of its employees, to the extent that those who left its portals decades ago still carry water for it when someone attacks the agency.

Symantec president and chief executive Greg Clark has suddenly left his post before a permanent replacement was in place, with the company naming director Richard Hill as a temporary fill-in. Clark was the fifth top executive to quit in the last six months.

A group, which has been given the name Buckeye, was in possession of, and utilising, NSA exploits well before they were leaked on the Web by the Shadow Brokers, the American security firm Symantec claims.