A trojan that affects OSX is being circulated within pirated software earning the name the “Pirate Trojan”. This is a trojan that first showed up in pirated copies of OSX called iWork09 Trojan.

Pirated versions of Adobe Photoshop currently in circulation are the latest carriers of the Trojan. The attack had previously been limited to pirated copies of Apple’s iWork suite. The trojan disguises itself as part of the application’s installer package. Once installed on a system, the malware launches a “back door” program which allows an attacker to remotely access a targeted system. This strategy has been used for years in pirated Windows software.

“The Attack could indicate a new phase of malware activity within the MacOS X World.” said Pedro Bueno from McAfee in a recent blog post. He also wrote “Before this we saw mostly lame malware for Mac OSX, but the iWork09 Trojan represents a new element to Mac Trojans, sophistication”.

The trojan has peer to peer-like characteristics and even encrypts its traffic. It looks like regular traffic going in and out of the infected machine.

Be careful when running installing any software. Make sure it’s from a good source.