Estafa, Spanish for “to rip off” in the sense of taking advantage of someone or stealing, comes from the Italian staffa, which means “stirrup”. This change of meaning came about because it was common, back in the day, for people to borrow a horse… and then never return it.
The Italian staffa itself comes from the Proto-Indo-European root stebh, which meant “to fasten, or place firmly” from which we get the English… staff. A staff, after all, is a stick that helps you fasten something into place! At least, it used to.
The st-f root is visible in both estafa and staff.