Let me quote:
Lastly, there is also a free test available online for people to check out. It essentially looks at your system’s performance and then lets you know whether your computer is being used for any shady activity or not.
But the author didn't say where to get this free test.
Anyways, common sense will dictate that you need to install anti-virus to protect yourself against these hackers. As for crypto mining, just don't go and click any suspicious link you found around the web. If you feel something's not right on your pc (high-temp, not responding, very slow) then its time to unplug and run some diagnostics.