Apple has issued a promised security update for the MacDefender family of malware.
The 2.36MB update for Mac OS X 10.6.7 doesn't require a reboot and adds malware detection and removal functions for all known variants of the MacDefender scareware. It also adds a delivery mechanism for updating malware definitions should new variants be spotted in the wild.
File quarantine features were added to Mac OS X in Snow Leopard, enabling the examination of files downloaded in Mail, iChat and Safari in order to protect against malware.
The update adds MacDefender definitions to the file quarantine function, as well as allowing further definitions to be added as and when they become available.
If you install the update on your Mac and it detects that you have already downloaded a MacDefender variant it will be automatically removed.
"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," a note on the Apple Support website reads.