Viruses depend on their hosts at every stage of their life cycles and must therefore communicate with them via protein-protein interactions (PPI). To investigate the mechanisms of communication by different viruses, we overlay reported pairwise human, virus PPI on human signaling pathways. Of 671 pathways obtained from NCI and Reactome databases, 355 are potentially targeted by at least one virus. The majority (268) of pathways is linked to more than one virus and a large number of the proteins frequently targeted by viruses are already known drug targets. We find qualitative evidence for the hypothesis that the proteins that viruses are interacting with in each pathway are not necessarily the same. For example, the pathway involved most frequently in an interaction with any virus, the TGF-β pathway, is linked by 18 viruses involving 50 different proteins, and none of these proteins is known to bind to proteins derived from all 18 viruses. Thus, our analysis provides biological hypotheses that can be tested quantitatively by statistical means and validated experimentally.