With icons you have to take great care not to encroach on other copyrighted material.
A long time ago the avast had a stylised a icon that had to be changed as it was too close to something someone was already using and I liked that one (image1). Things change.
They aren't looking for suggestions, they have already made the changes and it should be on avast web pages, facebook, twitter, etc. also. So it isn't only the AV that they are concerned with.
As for your "maybe this beautiful logo for avast" image that icon is already in use on the avast.com home page (image2).
