First rootkit for MacOS X

Opener, aka Renepo-A, has just appeared. TheRegister summarizes the situation : It's a shell script that must be installed on a Mac running OS X in order to work. It erases some commands of the Terminal and steals passwords, in copying the keys typed on the keyboard. It doesn't spread (it can't exploit a security hole to move from one Mac to the other, and must be manually installed on the target), what makes it more a Trojan than a Virus. It seems it allows an access to the machine thanks to VNC.
MacInTouch has more details about this script.
The risk of being infected by this piece of software is anyhow very low, since it needs either somebody with a physical access to your Mac, or someone able to make you execute it with administrator's right (i.e. to make you launch a program then type your password), or install it by yourself.