Some of the major companies that provide the basic infrastructure that makes the internet work have seen an increase in DDoS attacks against them, says Bruce Schneier. He adds that these attacks are of much larger scale -- including the duration -- than the ones we have seen previously. These attacks, he adds, are also designed to test what all defense measures a company has got -- and they ensure that the company uses every they have got, leaving them with no choice but to demonstrate their defense capabilities to the attacker. He hasn't specifically shared details about the organizations that are under attack, but what little he has elaborated should give us a chill. From his blog post: [...] This all is consistent with what Verisign is reporting. Verisign is the registrar for many popular top-level Internet domains, like .com and .net. If it goes down, there's a global blackout of all websites and e-mail addresses in the most common top-level domains. Every quarter, Verisign publishes (PDF) a DDoS trends report. While its publication doesn't have the level of detail I heard from the companies I spoke with, the trends are the same: "in Q2 2016, attacks continued to become more frequent, persistent, and complex." There's more. One company told me about a variety of probing attacks in addition to the DDoS attacks: testing the ability to manipulate internet addresses and routes, seeing how long it takes the defenders to respond, and so on. Someone is extensively testing the core defensive capabilities of the companies that provide critical Internet services. Who would do this? It doesn't seem like something an activist, criminal, or researcher would do. Profiling core infrastructure is common practice in espionage and intelligence gathering. It's not normal for companies to do that. Furthermore, the size and scale of these probes -- and especially their persistence -- points to state actors. It feels like a nation's military cybercommand trying to calibrate its weaponry in the case of cyberwar. It reminds me of the US's Cold War program of flying high-altitude planes over the Soviet Union to force their air-defense systems to turn on, to map their capabilities.