On-Premises

Securing the server

Create a complex root password

This will withstand brute force attacks by hackers to obtain the password.

Install ClamAV

Use Yast to install ClamAV and it's offline database.

Update database and run a complete scan.

freshclam
clamscan -r -i /

Delete all infected files, if any.

Restrict ssh access by key alone

Copy the file authorzied_keys to /root/.ssh

Edit the file sshd_config

vi /etc/ssh/sshd_config

and add the following lines:

PasswordAuthentication no
ChallengeResponseAuthentication no

If root access is not permitted, check Login as root to fix the issue.