Please, Help me

Recently, I’ve been having problems with a virus I can’t get rid of. I’ve run a full virus scan with avast but the virus is still on my computer. This message pops up about every 30-60 minutes https://imgur.com/a/LufLRct and it’s very concerning. But that’s not it, every time I do a search on google this pops up https://i.imgur.com/CDlJbmX.png I’ve never had this problem since I’ve been suspicous of having a virus on my computer and all of those seem to lead to a webiste called www.googleadservices.com which doesn’t really exist. I’m very worried and I’d appreicate help from anyone.

What router do you have?

MikroTik router

https://www.zdnet.com/article/thousands-of-mikrotik-routers-are-snooping-on-user-traffic/

https://www.zdnet.com/article/mikrotik-routers-enslaved-in-massive-coinhive-cryptojacking-campaign/

https://www.symantec.com/blogs/threat-intelligence/hacked-mikrotik-router

70+ different types of home routers(all together 100,000+) are being hijacked by GhostDNS
https://blog.netlab.360.com/70-different-types-of-home-routers-all-together-100000-are-being-hijacked-by-ghostdns-en/