UPDATE 4/10/2012: After dealing with a colleague who’s Mac was flagged as being infected with the Flashback malware, I found that the process of checking using aforementioned Terminal commands might not fully detect the infection. In addition the Terminal commands, you can also use the web-based utility provided by Dr. Web, which immediately detected it on my colleague’s iMac. You can visit the page at this link.
In the meantime, you can do a few things to protect yourself from the Flashback trojan. First, download the Java fix that Apple recently released. Open System Preferences and select Software Update. Click the Check Now button. It should show Java for OS X 2012-001 (version 1.0) as an required update.
UPDATE 4/6/2012: Apple has released another update for Java that shows as Java for OS X 2012-002 when you run Software Update.
UPDATE 4/12/2012: Apple has released a new Java security update that removes the most common variants of the Flashback malware. It will show up as Java for OS X 2012-003 when you run Software Update.
Second, if you know for sure that you have no need for Java, it can be disabled by going to /Applications/Utilities/Java Preferences. Uncheck the box(es) next to the Java runtimes that are listed. Once those box(es) have been unchecked, anything that requires Java will not run until you check the box to enable it.
Finally, if you are the extreme paranoid type, download and install a FREE antivirus solution for OS X. There are several to choose from such as Bitdefender Virus Scanner, ClamXav, Sophos or PC Tools iAntiVirus.
Bottom-line, this is not the end of world for Mac users nor is it a sign of the Apocalypse. More than anything, it is a reminder that OS X, just like Windows, requires a small amount of maintenance and care to avoid these issues.