The Day the Telnet Died
A single hour changed the internet's attack surface forever. Here's what happened.
Deep Dive
On January 14, 2026, global telnet traffic collapsed by 83% in a single hour, dropping from ~74,000 to ~11,000 sessions. GreyNoise data shows a permanent 59% reduction, with 18 major ASNs and 5 countries dropping to zero traffic. Evidence points to major US transit providers implementing port 23 filtering, crippling botnets like Mirai that rely on telnet for spreading via default credentials.
Why It Matters
This single infrastructure change likely disabled a massive swath of existing IoT botnets and will force malware authors to find new infection methods.