Recently, a variant of the trojan known as "Flashback" has been discovered that uses a Java Vulnerability in Mac OS X and makes it possible for malware to harvest user names and passwords from Mac users. This particular trojan has been through several variations, and the malware creators continue to tweak the trojan in an attempt to circumvent detection and infect more systems. The current best estimate of the number of systems infected is over 600,000 systems world wide.

Even on systems that have received an update to Java, the trojan will present a fake certificate in an attempt to trick the end user into installing the trojan.

To determine if the trojan is present on your machine follow these steps:

1. Open the Terminal application on your Mac, type the following and press Enter:
   
   
   defaults read /Applications/Safari.app/Contents/Info LSEnvironment
2. If you receive the message "The domain/default pair of (/Applications/Safari.app/Contents/Info, LSEnvironment) does not exist" type the following and press Enter:
   
   
   defaults read ~/.MacOSX/environment DYLD_INSERT_LIBRARIES
3. If you receive the message "The domain/default pair of (/Users/joe/.MacOSX/environment, DYLD_INSERT_LIBRARIES) does not exist" your Mac is safe and free from the "Flashback" trojan.

If you receive any message other than the ones listed above, you will want to follow the full instructions for manually removing the trojan.