Thanks @dave van Hoorn. Solved easily by adding the above code to functions.php.
I second what Calosea has said above.
You haven’t been hacked, this is just referral spam so you can chill. It’s quite common. I have this on multiple GA accounts, multiple platforms, hosting environments. You don’t need to worry about it. You’ll also start to see other such ghost GA data – a lot of which comes from Russia. It’s fake data pushed to your account.
Bit more annoying now it’s porn (started this last week on recent GA account no’s) – especially if sharing GA data with new clients!
Once you get a decent amount of traffic to a site you stop noticing it.
