It's real publications. If you ask for an obscure or new paper that nobody has gotten before you can get routed through e.g. a Russian university library portal

It's real publications. If you ask for an obscure or new paper that nobody has gotten before you can get routed through e.g. a Russian university library portal as if you were a student. Then sci-hub and apparently libgen will save copies to avoid doing it next time. The fact that all scientific articles have a doi number makes the whole system very simple.