Who’s using your Mac? Little Snitch tells all

Wednesday, January 7, 2009 | Articles | Read or Post a Comment

Have you ever wondered who’s using your Mac besides you? Those little blinking lights on your router might be telling you something. Some software on your Mac phones home without telling you it’s using your phone to place the call. Little Snitch acts like a reverse firewall to protect your Mac from the inside out. How does it do what it does?

Firewall

Your Mac connects to the rest of the world through a few thousand ports. For example, port 80 is usually how Safari connects to web sites and downloads web pages. Your Mac’s firewall closes most of the open ports which makes your Mac secure from outside intrusion.

What about intruders already on your Mac who are trying to connect from your Mac to the outside world? Your Mac’s firewall doesn’t stop that. Little Snitch does.

Privacy First

Sure, I’m concerned about outside hackers or robots or whatever and whomever trying to crack into my Mac. That’s why I have a firewall, a router, and a big stick by the door.

Many Mac applications and utilities connect to the internet from your Mac and don’t tell you what they’re doing or why.

As soon as you’re connected to the Internet, applications can potentially send whatever information they want to wherever they want.

Surely, they do this for good reasons, right? Right. Mostly. What shocked me when I installed Little Snitch was the sheer number and frequency of apps and utilities using my Mac’s connection to the internet.

Sometimes they do this for good reason, on your explicit request. But often they don’t. Little Snitch allows you to intercept these unwanted connection attempts, and lets you decide how to proceed.

Approved List

What Little Snitch does, at a basic level, is intercept all those outgoing requests to the internet, regardless of which port they use on your Mac, then it tells you who they are, which port they’re using, and asks what you want to do about it.

Little Snitch informs you whenever a program attempts to establish an outgoing Internet connection. You can then choose to allow or deny this connection, or define a rule how to handle similar, future connection attempts. This reliably prevents private data from being sent out without your knowledge.

Little Snitch

Configuring Little Snitch is a bit of a chore. It asks you what to do with each outgoing request. That can be cumbersome but the detail is fascinating.

Little Snitch provides flexible configuration options, allowing you to grant specific permissions to your trusted applications or to prevent others from establishing particular Internet connections at all. So you will only be warned in those cases that really need your attention.

Each application or utility that tries to connect to the internet, for whatever reason, is flagged. You can set specific parameters for each. Then it’s set it and forget it and Mac life is much easier.

Preferences

Setting up Little Snitch requires little effort. Download, unzip, install, and, uh oh, restart. Little Snitch works in the background. In typical Mac fashion, Preferences are straightforward and nominal (click any image for a pop up, close up view).

Little Snitch

Stop, Start, set alerts, set the floating onscreen monitor (or not), and lock down Little Snitch from tampering. Basic stuff.

The Rules List

In a way, Little Snitch nags. It’s constantly telling you when an application or utility wants to use the internet, for whatever purpose. If you have lots of software, there could be plenty of nagging.

What’s important is to set up the list of rules in the configuration window. Fortunately, that’s not difficult or time consuming.

Brand new configuration interface with full undo support, backup and restore functionality, powerful editing, searching and filtering capabilities, disabling of rules, text notes, and more.

Little Snitch

Click the Edit button in the Toolbar and change the accessibility settings for any app or utility on your Mac. Close it off entirely, have it warn you repeatedly, or set it for somewhere in between.

One of the things I found out quickly is that my Mac is chatty. It’s not that someone or something is trying to break in, it’s all the seemingly legitimate utilities trying to connect out from my Mac to God only knows where.

Easy Monitoring

Finally, once you set up Little Snitch to monitor your Mac, and determine which software is allowed to connect out from your Mac, you’d still like to know what’s going on but without repeated, nagging reminders, right?

A status icon in the menu bar provides a summary of current network activity, and a monitor window with more comprehensive information pops up automatically in case of new traffic events.

There’s also a pop up window which lists which software is making outbound calls from your Mac. It’s just a reminder, rather unobtrusive, but a steady reminder of how complex connecting to the internet can be.

I feel better using Little Snitch to monitor my Mac’s outgoing connections. Once it’s set up, the reminders and notifications are usually from new software, but not always.

It’s strange, but the Mac’s firewall is decent at preventing unwanted intruders, but does nothing to prevent the software already on your Mac from connecting outbound from your Mac. Little Snitch stops that.

Highly recommended for the paranoid, geeky, or very curious.

Reader Comments

Paranoid and Curious said:

This is a unique tool.
I have the same questions Stephen Keese asked.
Does any one know why Firefox or Camino must call home?

Does Little Snitch call home but not telling us?

#1 | Thursday, May 15, 2008

Jan Kemmer said:

I’m astounded at how much talk is going on FROM my Mac TO someplace else. Microsoft Office checks to see if there are other installs of the same serial number on the network. Camino needs to visit Mozilla before it even will run. I understand the need for an app to check for an update, but what else is going on that requires so many checks? Little Snitch blocks outgoing access, but I fear there is more going on behind the scenes with our software and our information.

‘If everyone is out to get you, then paranoia is the right attitude.’

#2 | Wednesday, May 14, 2008

Stephen Keese said:

I’ve been using Little Snitch for quite a while and am baffled by the information that it presents.  For example, almost all Apple apps try to connect back to Apple.  Why?  On launch Camino asks to connect to Mozilla.  If I click no, Camino won’t work.  Have you found any way to find out what the sites are for and what the connections to them are for?  What good is private browsing or erasing history, if everything gets sent to a server anyhow?  Even if the site says there is no personally identifiable information sent, is there any way to know if they are lying?

#3 | Wednesday, May 14, 2008

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