@Puck @mambi which version of Windows are you running?
Have either of you tried doing Repair of Avast or installing the previous version (with avast program updates disabled)?
I am aware Puck has also posted about the problem here: For a week or so, the firewall asks everytime if icarus.exe can connect even an allowed rule is set - #5 by Puck
I wonder if staff member @lukas.hasik can be alerted to this issue by Moderators etc.