class Paperclip::Validators::MediaTypeSpoofDetectionValidator

def validate_each(record, attribute, value)
  adapter = Paperclip.io_adapters.for(value)
  if Paperclip::MediaTypeSpoofDetector.using(adapter, value.original_filename, value.content_type).spoofed?
    record.errors.add(attribute, :spoofed_media_type)
  end
  if adapter.tempfile
    adapter.tempfile.close(true)
  end
end