There is a new malware made for Mac going around again. This new bug is a varient of the Flashback virus that first showed up in Sept. 2011. This new Flashback bug tries to exploit vulnerabilities in unpatched versions of Java running on your machine, so be sure to keep your JVM (Java Virtual Machine) up to date. If Flashback finds that Java is up to date, it simply asks the user to install an applet. The applet is accompanied by a self signed certificate that says it's issued by Apple, but the certificate clearly states "This root certificate is not trusted". This Flashback varient is after your banking information, so beware. One symptom of the varient having been installed is applications like Safari and Skype will become unstable and begin crashing often.