Some interesting analysis by Parth Shukla twitter.com/pparth | www.linkedin.com/in/parth-shukla-59583b20/:
Apparently most of the routers were Chinese. No surprise there.
Articles by others on the same topic
The Carna botnet is a network of compromised computers that was used for unauthorized scanning of devices connected to the internet. It was discovered in 2012 and is primarily known for its large-scale surveillance of the Internet of Things (IoT) and other devices. The botnet was named after the project "Carna" which was created by a group of researchers who used it to conduct a study on the security and prevalence of various devices on the internet.