SecureMac Security Advisory for Apple OS X

SecureMac has discovered multiple variants of a new Trojan horse in the wild that affects Mac OS X 10.4 and 10.5.

New OS X Trojan Horse Found in the Wild AppleScript.THT Trojan Horse

Las Vegas, NV - SecureMac has discovered multiple variants of a new Trojan horse in the wild that affects Mac OS X 10.4 and 10.5. The Trojan horse is currently being distributed from a hacker website, where discussion has taken place on distributing the Trojan horse through iChat and Limewire.

President Nicholas Raba stated, "The increased number of threats, security advisories, and security updates is an indication that Mac users must pay attention to computer security issues. As Apple's market share continues to grow, so will security research and hack attempts against OS X".

The Trojan horse runs hidden on the system, and allows a malicious user complete remote access to the system, can transmit system and user passwords, and can avoid detection by opening ports in the firewall and turning off system logging. Additionally, the AppleScript.THT Trojan horse can log keystrokes, take pictures with the built-in Apple iSight camera, take screenshots, and turn on file sharing. The Trojan horse exploits a recently discovered vulnerability with the Apple Remote Desktop Agent, which allows it to run as root.

The Trojan is distributed as either a compiled AppleScript, called ASthtv05 (60 KB in size), or as an application bundle called AStht_v06 (3.1 MB in size). The user must download and open the Trojan horse in order to become infected. Once the Trojan horse is running, it will move itself into the /Library/Caches/ folder, and add itself to the System Login Items.