Bacteriophages are viruses. Phages are viruses. It has long been debated whether viruses are "alive" because they do not have the machinery to survive or reproduce independently. However they do take over the command centers of our cells, and insert their genetic code into ours, and that of every other living thing. So no matter whether or not they are "alive"....they are a force to be contended with!

PS, where'd you get that "complex molecule" definition?