Thanks for the tip on the Fred Cohen paper. I have seen arguments to the effect that since a virus doens't run with an infinite memory, you can indeed determin

Thanks for the tip on the Fred Cohen paper. I have seen arguments to the effect that since a virus doens't run with an infinite memory, you can indeed determine whether a disk file represents a virus or not. As Alfred North Whitehead once said: "Necessity is the mother of invention" is a silly proverb. "Necessity is the mother of futile dodges" is much nearer the truth."