automeal

Ive noticed how by default almost every browser now has an autoplay video/mp3 function. Curious, has this already been exploited? If so how?? Is there a way to embed a back door in such video, and once link is clicked, instead of them accepting a pdf or something liek that, the autplay possibly could exploit through the browser and manage to reach the system, or even just browser would be of salt. thanks, hope to have some great responses on this subject!