Hence a good anti-virus program, ad-blocker, malware scanning, use of a higher-security engine like DuckDuckGo (who also have a browser though I stick with Firefox with extra security add-ons), avoidance of anything Google wherever possible and (big inhale)
...purchase a Virtual Private Network application (VPN) where not even your internet provider knows what you do. None of the free ones are worth a crap but I got Surf Shark with unlimited protection for all connected devices, at $52 for two whole years.
It's outstanding - allowing me to watch nearly any movie within two weeks of being in theaters without the IP or entertainment lawyers pounding on the door (I delete all after viewing just in case NSA's onto that, too).
Bottom line - NO computer invasions for years even after having to use Windows 10 that came on the screamingly powerful refurbished laptop I bought from Amazon for a pittance. Buying that VPN (along with using those above mentioned FREE measures) not only bought security but also peace of mind.
I use SOPHOS