Ohai HN.
Out of curiosity one day I started grabbing from my devices / servers logs the login attempts that were made.
From there I made a list of the IPs that tried to log in the most, and the user that was used.
I made a nice map that you can see on the repo - and feel free to suggest a use / improvement - or to contribute with your logs too (just the IPs and users, not your original logs files - see the README).
Cheers.