LONDON — A German magazine lifted the lid on the operations of the National Security Agency’s hacking unit Sunday, reporting that American spies intercept computer deliveries, exploit hardware vulnerabilities, and even hijack Microsoft’s internal reporting system to spy on their targets.

Der Spiegel’s revelations relate to a division of the NSA known as Tailored Access Operations, or TAO, which is painted as an elite team of hackers specializing in stealing data from the toughest of targets.