The update is available via Software Update or direct from Apple It is a 1.09GB file that requires users be running any version of Snow Leopard from Mac OS X 10.6 to Mac OS X 10.6.7.
Apple said the update is recommended for all users running Mac OS X Snow Leopard, and that it includes general operating system fixes that enhance the stability, compatibility, and security of the Mac. The fixes included in 10.6.8 include:
Enhancements to the Mac App Store to get prepare to upgrade to Mac OS X Lion
Resolves an issue that may cause Preview to unexpectedly quit
Improved support for IPv6
Improved VPN reliability
Identifies and removes known variants of Mac Defender
With this week's release of Final Cut Pro X, Apple even recommended that users be running Mac OS X 10.6.8, even though it had not yet been released. The last beta of the operating system update was supplied to developers earlier this month with no known issues.
The "MAC Defender" malware was previously addressed by Apple in a separate security update, 2011-003, released at the end of May. Hackers and Apple have been engaged in a back-and-forth battle as the software has spread through search engines like Google through a method known as "SEO poisoning."