Apple Releases Security Update To Remove MacDefender

Apple has released security update 2011-003 to address the recent increase in MacDefender malware targeting Mac OS X.

Security Update 2011-003 is recommended for all users and improves the security of Mac OS X.

Apple security update 2011-003 (only for Snow Leopard) consists of three components:

File Quarantine
Available for: Mac OS X v10.6.7, Mac OS X Server v10.6.7
Impact: Definition added
Description: The OSX.MacDefender.A definition has been added to the malware check within File Quarantine.

Automatic Updates
Available for: Mac OS X v10.6.7, Mac OS X Server v10.6.7
Impact: Automatically update the known malware definitions
Description: The system will check daily for updates to the File Quarantine malware definition list. An opt-out capability is provided via the “Automatically update safe downloads list” checkbox in Security Preferences.

Malware removal
Available for: Mac OS X v10.6.7, Mac OS X Server v10.6.7
Impact: Remove the MacDefender malware if detected
Description: The installation process for this update will search for and remove known variants of the MacDefender malware. If a known variant was detected and removed, the user will be notified via an alert after the update is installed.

Mac OS X malware list is now updated daily in the background without the need of a manual software update:

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.

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. After MacDefender is identified and removed, the message will be displayed the next time an administrator account logs in.

You can find out more details over at Apple.

https://support.apple.com/kb/HT4657