Sounds like Lykke Li, El Perro del Mar, Charli XCX and Sky Ferreira blended alltogether in a synthpop blender.
Legal name Tove Nilsson, she's from Sweden (best musicians' country ever), she belonged to a group called "Tremblebee". Little is known about her, her debut viral-buzz track is called Habits, and it sounds really good:
It was really talked through music blogs, but her recent and debut single is called "Out of Mind" and it's just mind-blowing.
Watch the official video below: