Norton just released a Flashback Trojan detection and removal tool for MacOS. If you have a Mac device, I strongly advice you to check if you are infected.
Initial reports stated that more than 600,000 Macs were infected by the Flashback Trojan. Norton can confirm that the number is trending downward but as of 12 April, there were approximately 270,000 machines still infected. The vast majority of these infections are in the US.
PS: Apple have also released a Java update to remove the Flashback malware. You should see it after running software update.