Magento 2 fake customer order came through with weird code instead of customer name

Just had a fake order come through on my Magento2 website. The address is nonsense and instead of a customer name it had this code:

{{var this.getTemplateFilter().filter($order.shipping_address.city)}}{{var this.getTemplateFilter().addAfterFilterCallback($order.shipping_address.last_name).filter($order.shipping_address.city)}}

Can anyone tell me what it was they’re trying to do? There’s no payment details attached, it looks like they didn’t go through to payment.