A computer virus is very similar to a biologic virus in many ways. When it comes to eating neither a biologic or software virus does that, and their way of reproduction comparable. A biologic virus however is not alive, it is simply set of chemicals that reproduce by hijacking living cells. If a biologic virus is not alive then a computer virus is not.

There are however no definition of what is life and what is not.

There are more to read about this subject in http://www.ibiblio.org/jstrout/uploading/philolife.html