Apple on Monday released security updates for its older "Leopard" operating system along with a Flashback Removal Security Update.
The Leopard Security Update
disables older versions of Adobe Flash Player that don't contain the latest security updates, prompting you to upgrade instead.
The Flashback Removal Security Update
finds and removes the most common variants of the malware.
Both updates are available directly from Apple's website or via Software Update; each requires Mac OS X 10.5.8.