Apple has released new security updates that check for and remove the common Flashback malware variants.
I highly encourage Snow Leopard and Lion users to run Software Update and get the official Apple tool.
What does it do?
FlashbackChecker runs the tests described in the F-Secure bulletins:
Variant i and
Variant k as of April 6th, 2012.
Note This utility checks and reports the presence of Flashback malware, it does not remove it!