Apple has today released the promised security update which tackles any installations of a recent spate of malware applications. The update labelled Security Update 2011-003 for Snow Leopard is available from Apple's website or Software Update.
Apple has also posted a knowledge base article explaining what the security update does and how it will help tackle similar variants of Mac malware in the future, also included is a detailed look at the file quarantine function that was built into both Mac OS X Leopard and Snow Leopard.
The update will also enable a locally stored list of malware to be updated daily, the list is used during the safe download check to determine if a file contains malicious software.
Apple maintains a list of known malicious software that is used during the safe download check to determine if a file contains malicious software. The list is stored locally, and with Security Update 2011-003 is updated daily by a background process.
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Security Update 2011-003 provides additional protection by checking for the MacDefender malware and its known variants. If MacDefender malware is found, the system will quit this malware, delete any persistent files, and correct any modifications made to configuration or login files.[...]