Apple has released Flashback Removal Security Update and Leopard Security Update today.
Flashback Removal Security Update for Mac OS X 10.5 removes the most common variants of the Flashback malware. If the Flashback malware is found, a dialog will notify you that malware was removed. In some cases, the update may need to restart your computer in order to completely remove the Flashback malware. Flashback Removal Security Update for Mac OS X 10.5 is a 1.23MB download.
Leopard Security Update 2012-003 disables versions of Adobe Flash Player that do not include the latest security updates and provides the option to get the current version from Adobe’s website. It’s a 1.11MB download.
Both updates are available via the Software Update component of Mac OS X’s Systems Preferences app. Each update requires Mac OS X 10.5.8.