In France, and most ‘old’ countries, we call people who turned turned rich over night ‘nouveaux riches’.
The term can also be used in a derogatory fashion, for the purposes of social class distinction, to describe persons with newfound wealth and who are viewed as lacking the experience, finesse, or taste to use wealth in the same manner as old money – persons from families who have been wealthy for multiple generations. The implication is that, despite their wealth, they are still of lower- or middle-class origin, and therefore culturally inferior. A stereotypical example would be persons with new wealth who spend money conspicuously, aspire to the tastes of their betters, or fail to disguise lower class preference.
Coming from the middle class myself, I find this despicable, but I think it’s a perfect description for the Google new office in Zurich. Tons of cash but no style or substance and trying way too hard to be cool. I actually find it risible.