Answer to question is NO, as trojans directly comunicate to your Machine no matter if you are behind VPN or not. The best solution if Hardware Firewall and in some cases NAT settings on Router where you route all non wanted incoming connections to non desired ports into Black hole (Non existing local IP and Port.

You can test things up a bit using https://www.grc.com/shieldsup which also have some explanations of terminology.

Many online VPN service providers actually do offer some form of malware protection on their paid products. They can do this because your web browsing is going through their network so they can monitor your activity and block some known malware, e.g. websites that are known to host malicious content. I can't imagine it being anywhere near as effective as having good antivirus software on your own computer though.

If this is not a SPAM-Question the answer is:
No.

https://en.wikipedia.org/wiki/Vpn

I have been experiencing poor performance in my laptop and it often gives me warnings (my anti-virus). I guess there are viruses in my laptop but I don’t understand how there could be one as I always had anti-virus activated. Recently I went through VPN services and most of them said something about protection, Does VPN offer protection against Virus?