

And also:
But if you ignore the warning and go ahead with the login, the attacker does three things:
- Steals your password
- Opens a connection to your server and observes each command you type (MITM)
- Opens a second connection to your server and infects it with Ebury
Don’t use passwords for your SSH. With key based auth your session would still have been intercepted and relayed, but the attacker can’t make arbitrary new sessions, because they don’t get your private key.

Not a bad idea, only they are going to keep the wrong ones, the cheerleaders instead of the skeptics.