Alastair Reynolds's Revelation Space sci-fi novels include mysterious communications from beings that want to cross into our reality from another universe or timeline (I forget which) and need our help to do so.
Coincidentally I read that just as rowhammer hit the news. Maybe we could do something similar to gain access to other simulations running on the same hardware.
Alastair Reynold's novels have so many really interesting and cool ideas in them.
I think the greenfly are what you're thinking of, but in that series, there was also the case of a neutron star that was entangled with itself and functioned as a giant, time-independent computer.
Coincidentally I read that just as rowhammer hit the news. Maybe we could do something similar to gain access to other simulations running on the same hardware.