Mirai IoT Botnet Knocks Out Dyn Managed DNS
On 21 October 2016, waves of DDoS traffic from the Mirai botnet hit Dyn's Managed DNS platform, making Twitter, Reddit, GitHub, Netflix, PayPal and other Dyn customers unreachable for many users in North America and Europe.
02Deep-Dive Technical Analysis
Mirai infected cameras, DVRs and home routers that exposed Telnet with unchanged factory-default passwords, building a botnet that peaked at about 600,000 devices; its source code had been posted publicly weeks before. Dyn reported major attack waves of roughly 11:10–13:20 and 15:50–17:00 UTC using TCP and UDP traffic on port 53, amplified by legitimate recursive resolvers retrying failed lookups, and estimated as few as ~100,000 malicious endpoints. Because many large sites used Dyn as their only authoritative DNS provider, one provider's outage became a regional Internet outage.
03Vulnerability & Exploit Flow
Botnet of IoT devices with default credentials flooded Dyn's DNS, compounded by resolver retry storms.
04Recommended Defense & Mitigation Protocol
Secondary authoritative DNS providers, anycast scrubbing capacity, ISP source filtering (BCP 38) and elimination of default IoT passwords.
05Security Impact & Geopolitical Consequence
Showed that insecure consumer IoT on residential broadband could take down core Internet naming infrastructure, driving multi-provider DNS adoption and IoT default-password regulation.
06Authoritative Standards & External References
07Related Topic Cluster Records
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