National Intelligence Director James Clapper has said it appears a "non-state actor" was behind a massive cyberattack last week that briefly blocked access to websites including Twitter and Netflix.
At the Council on Foreign Relations in New York on Tuesday, Clapper said investigators are gathering a lot of data, and preliminary indications are that a non-state actor is to blame. But he said he wouldn't want to completely rule out whether a nation-state might have been behind it.
Last Friday, cyberattacks crippled a major internet firm, repeatedly disrupting the availability of popular websites across the United States. Members of a shadowy hacker group that calls itself New World Hackers claimed responsibility for the attack, but that claim could not be verified.
Homeland Security Secretary Jeh Johnson confirmed Oct. 24 the Mirai botnet was used to perpetrate the large-scale distributed denial-of-service attack, leveraging a worldwide network of connected devices to send junk traffic at one of the companies that manages internet traffic.
DHS is working with the intelligence community — through the National Cybersecurity and Communications Integration Center — and is developing "a set of strategic principles for securing the Internet of Things, which we plan to release in the coming weeks."