Nice memories of the TBAV/ThunderByte Anti-Virus story.
Together with Jeroen Smulders, I was sort of on the sideline in the early days as we both were at the university had access to FidoNet (I as host, other Jeroen as point), Internet, mailing lists and newsgroups.
I used it because it was the fastest Virus Scanner around and a need when scanning all incoming FidoNet data for viruses (I had seen at university what damage a spread could do).
Some VIRUS-L, comp.virus and book links from that past:
The Wiert Corner - irregular stream of stuff 