Apple has updated the malware protection built into its Mac operating system to flag a recently discovered trojan that hijacks users' machines by masquerading as a benign document. Malware disguised as an Adobe Flash installer, meanwhile, remained unchecked.
The file quarantine, which Apple snuck into a prerelease version of Snow Leopard in 2009, was updated to include a definition for Trojan-Dropper: OSX/Revir.A, which antivirus provider F-Secure disclosed on Friday. According to an update on F-Secure's blog, the malware disguises itself as a PDF file in an attempt to trick users into clicking on it.