Nah. They already existed much like the conspiracies about Judaism.

If there were conspiracies against a group, the Nazis went after them, because they had to keep finding a new group to blame when people's problems didn't disappear after the Nazis made their last target disappear.

Fascism needs a group to blame everything on, so they can never "win" they always have to have a boogeyman or else the people might blame the ones running the fascist government.