... while American companies were being warned away from supposedly untrustworthy Chinese routers, foreign organisations would have been well advised to beware of American-made ones. A June 2010 report from the head of the NSA's Access and Target Development department is shockingly explicit. The NSA routinely receives – or intercepts – routers, servers and other computer network devices being exported from the US before they are delivered to the international customers.
The agency then implants backdoor surveillance tools, repackages the devices with a factory seal and sends them on. The NSA thus gains access to entire networks and all their users. The document gleefully observes that some "SIGINT tradecraft … is very hands-on (literally!)".
Eventually, the implanted device connects back to the NSA. The report continues: "In one recent case, after several months a beacon implanted through supply-chain interdiction called back to the NSA covert infrastructure. This call back provided us access to further exploit the device and survey the network."