I’m not sure where they came from actually. I’m unable to see it if I look at the theme files directly, but if I upload it to a server I can see them just fine. They are located in the main folder, and the woocommerce folder. One of the files mentions something about WooCommerce, but I’m not sure if that’s how it got there or not.
If you’re using a PC there should be a way to show hidden files, last time I checked it was much easier to show them than on Mac (I’m using a Mac). If you have a way to upload them to a server then you should be able to remove them from the folders that way as well.
Here’s more info if you’re using a Mac – http://appletoolbox.com/2014/03/mac-os-x-how-to-remove-ds_store-files/