In an evolutionary sense, the concept of a life form intermediate between viruses and the types of unicellular organisms with which we are familiar is implausible, because viruses are parasitic on cells whose metabolic and biosynthetic machinery they co-opt in order to reproduce themselves.
Viruses are most unlikely, therefore, to be in any sense ancestors of cells.
On the other hand, the notion of an organism intermediate in complexity between a virus and typical cell raises an interesting question. If the latter assumption is correct, the earliest ancestors of cellular organisms must have been much simpler than cells of the type with which we are familiar. As Stuart Kauffman discusses in At Home in the Universe they would have lacked not only nucleic acids, but also proteins. Replaced, perhaps, by later and better adapted forms. Something much smaller might function effectively as a self-perpetuating chemical system of the kind envisaged by Kauffman.