The DDoS attack on Dyn took many major web sites offline for most of a day, including Twitter, PayPal, Reddit, Amazon, and Netflix. Millions of compromised IoT devices, belonging to the Mirai botnet, flooded Dyn’s DNS service with up to 1.2 TBps of bogus traffic, making it impossible to respond to genuine DNS requests for their customers’ web sites. The Dyn attack did not affect the PayPal or Twitter servers in any way, but these sites were unreachable for the vast majority of humans who prefer not to memorize IP addresses.
The attackers were not nation-state actors but rather garden-variety criminals with an axe to grind. “The perpetrators were most likely hackers mad at Dyn for helping Brian Krebs identify–and the FBI arrest–two Israeli hackers who were running a DDoS-for-hire ring,” Bruce Schneier wrote at the time.
Read how the growing legion of insecure IoT devices means that the next DDoS attack on the domain name system could be much more severe and why the centralization of DNS providers is largely to blame on CSO.