Exploit for Mozilla Firefox versions 1.5.0.4 and below. The demonstration exploit below will attempt to launch "calc.exe" on Windows systems, execute "touch /tmp/METASPLOIT" on Linux systems, and bind a command shell to port 4444 for Mac OS X Intel and PowerPC systems. An anonymous researcher for TippingPoint and the Zero Day Initiative showed that when used in a web page Java would reference properties of the window.navigator object as it started up. If the page replaced the navigator object before starting Java then the browser would crash in a way that could be exploited to run native code supplied by the attacker.