I can believe the latter part --- but to believe the first part, I'd have to know what happened to "the soup", and the other problem is that viruses are usually very specific to their host --- no matter how much your dog sneezes on you, you cannot catch the same cold they have in most cases.
"RNA-world" says that cellular life formed as parasites in the soup and ate it. Before then, the whole pond (or whatever) was something like one big organism.
The viruses today have survived by specializing, even as have the cellulars. Everything today is thoroughly modern.