A Java applet determines whether the victim's machine is running Windows, Mac or Linux, then downloads the appropriate malware for the platform. Researchers at F-Secure have uncovered a new Web-based attack that installs backdoors on Windows, Linux and Mac OS X computers.
"The attack was detected on a compromised website in Colombia, F-Secure senior analyst Karmina Aquino, said in a blog post on Monday," writes Computerworld's Lucian Constantin. "When users visit the site, they are prompted to run a Java applet that hasn't been signed by a trusted certificate authority. If allowed to run, the applet checks which operating system is running on the user's computer -- Windows, Mac OS X or Linux -- and drops a malicious binary file for the corresponding platform. The files are detected by F-Secure as 'Backdoor:OSX/GetShell.A,' 'Backdoor:Linux/GetShell.A' and 'Backdoor:W32/GetShell.A.'"

The link for this article located at eSecurity Planet is no longer available.