Did I buy a counterfeit Macbook charger?

I bought a cheap charger on eBay for my Macbook a month weeks ago. It was listed as a genuine apple charger, and I can't tell if it is or not. It overheated out of no where yesterday, made some crazy loud buzzing sound, and then just stopped working.

It mostly looks like an apple charger I think, but I don't have anything to compare it to. It says it's made by Apple withe the "designed in California" and "assembled in China" label, but it also says "Apple Japan" and "Delta Electronics" on one side. What do you think?