This is the Italian F-bomb. Literally means to go take it in the ass. If administered correctly, it can leave the opposition in complete shock and awe. It also helps to make the Italian gesture that is synonymous with this expression, which is to put one hand in between the bicep and forearm of the other arm and to raise that arm with the palm of that hand towards yourself. Extremely effective to those who understand it.
Tommy Salami: Ay, Tony, wheis duh fuckin money you owe me from duh ting at duh place wit dat guy dee odduh day?
Tony Rigatoni: Vafanculo.
Tommy Salami: ........