The chances of getting hacked in linux are very slim.
But you can use firewall like firestarter and lokkit. I use firestarter and its very easy to configure(dont have much options).
sudo aptitude install firestarter
OR
sudo aptitude install lokkit
Hi Guest we just wanted to alert you to a major change in the forum. We will no longer be allowing the posting of outgoing links. Please use the attachment feature to attach media to your posts.