Help to Remove SmileFiles Pop-up Completely

I've stumbled upon a particularly nasty malware called SmileFiles, which doesn't seem to be very common based on some Internet searches I've done. It appears to be fairly new, and I'm unsure how to get rid of it. I got it earlier today while trying to download a PDF. However, when I turn on my computer, I get a pop-up on my desktop that looks like this: