Well, let's see: it would benefit Israel because it would drive the US away from the Arab world if we thought Arabs were responsible; the elected government of Israel would condone this to get the benefit of greater US dependency on Israel in the Middle East; and Mossad agents because that's who does CIA-type stuff for Israel.
But your questions miss the point; I suggested Israel as the guilty party not because I think it's so but because we know so little that it's remotely, in theory, possibly so. And if that's the case, we don't know enough to nominate anyone for the 'honor'.