Then What To Do?

It all boils down to common sense systems administration:

Mind your logs. You can read them yourself, or train a robot to. I use logsentry, other monitoring tools can be taught to look for anomalies (failed logins, etc)

Keep your system up to date. If not OpenBSD, check for the latest version, check what your system has and badger the maintainer if it's outdated.

And of course, configure your applications such as sshd properly -