Flashback Removal Security Update
This update 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.
To improve the security of your Mac, this update also disables the Java plug-in in Safari. For instructions on how to re-enable it, please visit: http://support.apple.com/kb/HT5241.
SHA1 = 64231192a3b6d0ac8b0fe61c6ea7be5c829cc9f9
Read more http://support.apple.com/kb/DL1534