http://tweedgbwjchsbiofbshntdnkkehlsuehkdkglu4jpr4fli5du33444qd.onion/2021/observing-a-botnet
The best option I found for this was bittorrent-dht , an easy-to-use Node.js implementation of DHT, and set off to work with little more than the example they give in the readme. Collecting data over the next day allowed me to discover another interesting trait of this botnet - its connections seem to be cyclical with the time of day.