Welcome to the Internet
Any system that's online for long periods of times will be a target for these types of automated attacks..
It's impossible to stop them all, you could sit at your system reporting each attacking IP for years and it wouldn't help much.. they're usually exploited systems running large scans against a certain range of addresses.
There are ways to make you look less favourable, i.e: enabling a firewall.. pf is my recommendation, in this case.. only allow connections to port 22 from trusted clients, you might not know the IP of every location you'll be connecting from.. so less annoying method would be running SSH on a different port number, if anything it'll stop 95% of the automated skiddies out there.
Good luck.