Twitter, SoundCloud, Spotify, Shopify, and other websites have been inaccessible to many users for most of the morning due to a major cyberattack. Box, Boston Globe, New York Times, Github, Airbnb, Reddit, Freshbooks, Heroku and Vox Media properties are among other sites experiencing issues after the attack. The outages are the result of a distributed denial of service attack (DDoS) on the DNS provider Dyn.
Dyn offers Domain Name System (DNS) services, essentially acting as an address book for the Internet. DNS is a system that resolves the web addresses we see every day into the IP addresses needed to find and connect with the right servers so browsers can deliver requested content, like the story you’re reading right now. A DDoS attack overwhelms a DNS server with lookup requests, rendering it incapable of completing any. That’s what makes attacking DNS so effective; rather than targeting individual sites, an attacker can take out the entire Internet for any end user whose DNS requests route through a given server.
According to this map provided by DownDectector, the attack is primarily impacting U.S. users, although users in Europe and Asia may experience problems as well.
The attack on Dyn is believed to have started early this morning. Service was temporarily restored, but a second attack knocked sites offline once again. The DNS provider says engineers are working on the issue.
The White House press secretary tweeted that the Department of Homeland Security is investigating the attacks.
— Eric Geller (@ericgeller) October 21, 2016
Security researcher Bruce Schneier reported in September that several internet infrastructure companies had been targeted with DDoS attacks, although they had not caused the kind of widespread outages experienced today. Shneier wrote that the attacks seemed designed specifically to test the defensive capabilities of companies that provide critical Internet service.
It still isn’t clear where that cyber attack originated or when or how it was likely to stop. It seems as though Americans may have to venture outside until Netflix is back up and running.