Router hijacked

My Router/modem has been hijacked and my Avast Premier security has been compromised as well. I can not select the browser of choice or other things. What does someone do in this case? Avast initially gave me the option to block the router that was hacking in, which I did, and then they hacked back in and took control of the Avast Premier. Any help out there?

For help attach requested logs

Logs to assist in cleaning malware https://forum.avast.com/index.php?topic=53253.0

What os/sp?
What exact version of avast?
Who/what is saying that your router has been hacked and avast is compromised?