Security researchers claim that the iServices Trojan Horse botnet, or iBotnet, has been activated. While this is the first known Mac specific piece of malware, it is not the first time that Mac OS has seen malware. The iBotnet, which was first discovered in January, is believed to be installed alongside pirated copies of Apple iWork '09 and Adobe Photoshop CS4.

Antivirus programs for the Mac, while not used my many Mac users, have been updated to remove the program. Infected users may notice an increased CPU usage as the iBotnet issues a denial-of-service attack against websites. It is a safe bet that users can also identify that they are infected by the illegal copy of software installed on their Mac.

In addition to the usage of Antivirus software, it may be possible to remove iBotnet by simply deleting the System/Library/StartupItems/DivX and/or System/Library/StartupItems/iWorkServices folders from your Macintosh hard drive. SecureMac is also offering a free tool for users to remove iBotnet.

It is believed that only a few thousand Mac systems are infected with the botnet and it is not a danger to the average Mac user.

Should Mac users run out now and purchase antivirus software? Not yet. While the number of Macs continue to grow, so will the number of attacks. Users can stay safe simply by following a few basic rules; these same rules also apply to users of Microsoft Windows:

• Do not download pirated software.
• Do not use your root or administrator account for daily usage.
• Keep your operating system and applications updated
• If not using a third party firewall, enable the one included with your OS. OS X, XPSP2, and Vista all have a basic firewall.
• Separate your Mac or "PC" from the internet with a router, even if you only own one system.

Of course, you can always get a jump start on the inevitable issues to come by purchasing an antivirus product. You may not need it for years to come, but better safe than sorry, right?