They are four Russian girls and they are called Gravitation (Гравитация).
Here‘s their website, with more decorous pictures. Oddly, it says nothing about repertoire. Nor do we learn their names,
Instead, we are told: ‘For fast price, contact Mikhail Smirnov’ (is that him, behind them?).
Here‘s some video of a Christmas jingle, with fairly ropy sound. And here’s a parting shot, for luck.