Interesting, that's a similar URL but slightly different. It makes me think Shopify has been compromised from the infrastructure level. 

We are Shopify Plus customers so I've alerted our Success Manager, we will see if that raises any alarm bells on their end. Most likely it's an app that's been compromised, and from what I can tell, not a serious issue, but something to monitor close...

Seems to be a widespread Shopify issue across especially Canadian Shopify stores. This Google search shows multiple sites compromised by this: https://www.google.com/search?q=instagram+kunghac&oq=instagram+kunghac&aqs=chrome..69i57j69i60.4522j0j1&sou...