I run Windows 10 professional on my pc and on a couple of laptops. I've also a Synology NAS and I sync a number of folders between the NAS and the pc / laptops using synology's cloudstation.

The virus / spyware  protections that I have are just the standard windows firewall, windows defender and paid malwarebytes.

Just wondering, is this sufficient or should I be using any paid anti-virus products - or do anything else for that matter. 

I'm naturally cautious when visiting websites and have never had any viruses or intrusions as far as I am aware.  I've not manually opened any ports, other than those required for cloudstation.