I'd reinstall ethos, creat a brand new account for your config or just use config maker. Change ethos ssh and root passwords.
Yes Sir . Maybe I can try this. Done with SSH and root passwords changing.
The safest way is to reinstall everything, set it up with new passwords, and make sure not needed ports are close on the machine (not familiar with EthOS but I guess it is a Linux).
If the machine is already infected with some kind of trojan horse, then changing the passwords won't help you...
format and re-install everything from scratch, and never use same passwords again (or similar ones)