Antivirus probably best takes place at the level of the network, not the individual computer. Or, to transcend binary thought, combine them, as independent, synergistic foci. At the network level, it is less the content of communication than the existence of the connection. That is information.
I’ve heard that 90% of what we do, we do every day. Strip out the 90% and you’re left with the 10%. That interesting 10% of difference from what’s expected.