Background: While trying to understand the Standard Model I stumbled on a paper that explained it in very simple terms. I recognized that I don't even understand the quantum mechanical way of the electric force. The paper pictured electromagnetic repulsion by two people on different boats, exchanging a bowling ball, one throwing, one catching. The bowling ball standing for an exchanged photon. That cannot be the whole of the truth, as it wouldn't, not even as a picture, explain the attracting force between two bodies with opposite charges.

Now the question: how is electromagnetic repulsion and attraction really modeled in terms of quantum physics?

Edit: the duplicates only address repulsion, or are out of reach for what I understand about quantum theory. So I state the missing part explicitly:

How is an electron attracted to a positron by the exchange of a photon?