The Windows 7 firewall accepts or blocks all outgoing connections. It is not possible to allow specific connections only. The firewall rules have no effect.
Too bad. Most backdoors in use nowadays wait until an outgoing connection is possible and then connect to the infested remote computer.
Though there is a workaround to block all outgoing connections and leave some trusted remote ports open.
Simply block every protocol and leave the trusted remote ports open:
- In the Windows Firewall Properties turn the firewall on for every profile.
- Block incoming connections (default)
- Accept outgoing connections (default)
|(Example: outgoing firewall rules with exceptions)|