Virus is a program, right?, so a program can be destroy by another program or virus (like natural source of life). No matter what kind of computer language you use o create o destroy a virus. Somewhere in the present there are few scientist (DARPA) that are developing a new structure for destroy virus with a mix of artificial intelligency and virus code, not its a fiction its totally possible.

Like a organic virus they improve their action when come external agent fight them (antivirus) and get more evolution, thats the result of Trojans and Worms(they can be improve with the mix of a destructive virus). The probability tell us that will be possible generate intelligence virus with self choices, so the challenge its to fight them. Virus are the most important warnings for the future of the information.