I've heard it could be electro, since there was a shock of lighting when he entered and left. Also, im pretty sure he was talking about the venom project (like in ultimate Spiderman), the cure for cancer that Richard parker and Eddie brocks father were creating( although for the purpose of the movie, it could have been curt Connors who was working with Richard parker) hence why the shadowed man came to curt Connors. Although, I suspect it could have to do with something much deeper about his father as the shadowed man asked specifically about his father. Curt also told the man to leave peter alone, maybe suggesting it also has to do with peter, like maybe something genetic. Another theory is that Richard injected peter with something as a boy (his research was all on spiders) which let him survive the spider bite and alterations to his DNA, although in the comics, it was peters natural autonomy that he survived the bite by chance.