You can block them with Avast (Free) Website blocking.
You need to see address in Web Shield when you start application.
For example to block Iobit Uninstaller I blocked following address with Website blocking :
update.iobit.com
For PotPlayer : .daum.net. I also had to block tracking cookie in IE10 since it uses IE to
connect with internet.
Hope this helps since Avast Web Shield is incompatible with Windows Firewall outbound rules.