Introducing Little Snitch

A firewall by default will protect your computer from incoming threats, which is obviously very important, however unless specifically configured it will normally consider all connections established in an outgoing direction as safe and therefore automatically allow them and their return traffic. This means that any application you have installed on your Mac will be able to send data out (and receive a response) to the Internet at any time, without your knowledge.

Now in a perfect world that would not be a problem, because every application you have installed on your Mac is from a trusted vendor/developer, right?

Unfortunately this is not the case and you will only realise this once you have an application like Little Snitch installed on your Mac.

Little Snitch is a lightweight and easy to use application that guarantees no application installed on your Mac will attempt to send any data out over the Internet unless you have approved it, therefore giving you complete confidence that your private data is staying private.

Once installed Little Snitch monitors your network connections and each time an application attempts to send data out over the Internet it will ask for user input.

You can now choose if you want to allow the applications to send the data and if you should be prompted again in the future.

Obviously this type of application requires a learning period and like any software firewall over the first few days you will be seeing a lot of the above prompt. However its worth persevering as once you are through the initial learning period Little Snitch will simply operate transparently always protecting you from threats.

It is also possible to see and make changes to all the rules you have defined using the simple "Rules" menu. As you can see from the screen shot below Little Snitch will automatically allow pre-approved applications, such as Mail and Network Utility etc (although you can re-configure these options if you wish).

I highly recommened everyone installs Little Snitch on their Mac. It can be purchased for under £20 from the Little Snitch website. They also offer a free trial so there is no excuse not to give it a try.