Two issues here. First, you've ignored the astronomical amount of computational resources required to evolve an intelligence from scratch and the minimum size of a viable intelligence, which each rule out the possibility of computer viruses or genetic algorithms becoming intelligent on their own. Second, you seem to have jumped from "evolution is the only thing that can create intelligence in a universe that lacks intelligence" to "evolution is the only thing that could make computers intelligent", ignoring the pre-existing human intelligence that could bypass the whole evolution bit.