‘Researchers at Sophos discovered that Apple updated the anti-malware protection built-into Mac OS X when it released a new version earlier this week.

Mac OS X 10.6.4 has been updated to provide limited protection against OSX/Pinhead-B (called HellRTS by Apple), a backdoor Trojan which can allow remote hackers to gain control over Mac computers for the purposes of identity theft, spying and the distribution of spam.

This malware was distributed disguised as the iPhoto application by malicious hackers.

Sophos researchers discovered that Apple updated a file called XProtect.plist – the file that contains elementary signatures of a handful of Mac threats – to detect HellRTS.

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