Here are a few more details

Looking in the system event logs showed these warnings

Name resolution for the name program.avast.com timed out after none of the configured DNS servers responded.

Name resolution for the name static.avast.com timed out after none of the configured DNS servers responded.

Name resolution for the name program.avast.com timed out after none of the configured DNS servers responded.

Name resolution for the name www.avast.com timed out after none of the configured DNS servers responded.

Name resolution for the name static2.avast.com timed out after none of the configured DNS servers responded.