Product Reviews

It is imperative to add protection to any computer that is connected to the Internet. Whether you are dialling an ISP or enjoying a cable or ADSL connection, your machine can be attacked. Intego claims NetBarrier X can solve most online security problems through its personal firewall, intrusion detection system and privacy filter. The CD contains two versions of NetBarrier: one for Mac OS 8.1 and higher and the other for Mac OS X.

The firewall section looks a bit like the interface for the popular shareware application BrickHouse. Individual services can be permitted or blocked, so you can allow Internet users to log in using SSH or to browse a Web site running on your Mac. By default it lets you connect to any kind of service on the Internet, but won't allow anyone on the Internet to connect to you. It also permits other systems on the local network to connect using TCP services, which includes Web, FTP and SSH.

The list of rules doesn't look pretty, but they are the heart of your system's security, and even the order in which they are listed is crucial. Rules are processed from the top down, with rules higher in the list taking priority. For example, in the default rule set in the main picture, you can see that all incoming connections from the Internet are blocked. And as NetBarrier counts local network connections as Internet connections, how can local users see the intranet Web site?

Well, above the blocking 'STOP' rule is one that specifically allows local network access. If that rule was moved down two levels, the server would be unavailable to everyone. If you move the rule that allows the 'Internet to access the Mac using all services' to the top you'll remove the bulk of your protection.

Working to rule

There is absolutely nothing wrong with this kind of rule system, and it is standard on the very best professional firewalls you'd find installed at an ISP. The rules can only be altered by someone with an administrator-level

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user account, which prevents untrustworthy users meddling with the settings.

The antivandal part of NetBarrier can block a number of attacks, and send attackers' IP addresses to a 'stop list', which effectively prevents them from connecting to your system, even to legitimate services.

The logic goes that when someone scans your system for open ports, they are intending to launch a more serious attack later. But they can't if your system doesn't respond to their IP address. A stealth mode hides your computer by stopping it replying to the Ping command, while other options are designed to prevent the nasty crashes that can occur when ping-based denial of service (DoS) attacks are launched. Having said that, we were able to repeatedly freeze our OS X server using a common DoS attack available from the Internet. To be fair, most personal firewalls fall when attacked like this.

NetBarrier's privacy section will warn you when you try to send sensitive information on to the Internet. You need to tell the program what the information is by entering the details into its database, and then, when you're browsing the Web and absent-mindedly type, say, your credit card details into a Web page and press Send, an alert sounds and you're asked if you intended to do this.

Theoretically, this prevents rogue applications stealing your data, but it won't stop someone who has logged into your Mac, even using a non-administrator account, because they can simply click on the Ignore button and continue as before (such naughtiness is logged, however). It doesn't warn or log when someone sends data out through SSH, the secure shell used to administer other systems, so be aware of this before giving individuals access to your computer.

Private chancer

The privacy settings also allow you to block Web adverts and cookies, as well as optionally feeding false information about the type of computer and Web browser you are using to the sites you browse.

The trusted list lets you specify IP addresses that can access your computer regardless of the firewall rules. However, this is a very dangerous feature to use. It is easy for an attacker to spoof an address from their machine and gain unlimited rights to port scan and attempt to log in.

NetBarrier X is relatively inexpensive and provides many more protection features than the average, plain personal firewall. It is an excellent option for anyone who is sensible enough to want to keep attackers at bay. Combine it with an antivirus program for maximum security.