tor installs itself on debian ?

I powered on whonix-gateway. And made new virtualmachine so all networking goes trough whonix-gateway. I used net-install iso to install new debian 9. I choose to install bare minimum debian os. When i did “service --status-all” i noticed that tor service is running. How is that ? Does debian installer somehow decides to install tor because i routing installation over whonix-gateway ?
If i install without gateway, there is no tor installed on debian.

I can’t imagine Debian installer has code to detect a Tor connection let alone being behind a Whonix-Gateway.

However this isn’t a Whonix question and could be sorted as per Free Support for Whonix ™.