The Infinite Brief

During an internal investigation, Amazon testers found a tiny microchip nested on the servers’ motherboards, not much bigger than a grain of rice, that wasn’t part of the boards’ original design.

Amazon reported the discovery to U.S. authorities. During the ensuing top-secret probe, which remains open more than three years later, investigators determined that the chips allowed the attackers to create a stealth doorway into any network that included the altered machines.

Multiple people familiar with the matter say investigators found that the chips had been inserted at factories run by manufacturing subcontractors in China.