I was on the Shopify admin page, on a different tab, and when I switched back it redirected me to the following url:
This NOT my store I have no idea what it is as it won't let me load it.
This seems suspicious, and I don't think it's on my end. I don't know if it's possible it's from an app I have or not. It's happened twice now in the last two weeks, so I thought you should be aware.