Following a report from last week on a new Mac trojan disguising itself as a PDF file, Apple has released an update to their anti-malware tools for OS X to remove the exploit if present, as well as prevent it from affecting Macs that are currently clean.
As with all malware updates, the revised malware definitions are automatically applied to all Snow Leopard and Lion systems with the latest software updates. The new malware definition is reflected in the above image. Hat tip to MacRumors for sharing!