The message users will now see if they accidentally try to install MacDefender, or one of its variants.

As promised, Apple's released a security update to address the MacDefender malware, as well as its known variants.

Security Update 2011-003, which went out to Mac OS 10.6 Snow Leopard users this afternoon, adds file quarantine and built-in removal of the MacDefender malware.

"The installation process for this update will search for and remove known variants of the MacDefender malware," Apple's support document reads. "If a known variant was detected and removed, the user will be notified via an alert after the update is installed."

The MacDefender malware, which also goes by the name of MacProtector, MacSecurity, and Mac Guard, appeared on the scene earlier this month. It pretends to be legitimate antivirus software, while posting fake alerts, and opening up pornographic Web pages in an attempt to get users to enter in their credit card information to clean up their computer.

Last week Apple posted details on how to identify and remove the software, while promising that a future Mac OS X update would protect users from the malware.