Default [Q] Heavy Data usage on play store

Two days ago I was unpleasantly surprised with sms from my mobile carrier that my internet service was disconnected because of heavy usage in the night before and making enormous un-billed amount. I checked data usage and it showed more than 5GB internet traffic on play store. At that time I didn't use my phone and I have no idea how all that traffic was spent. I've checked in the mobile carrier and they gave me the URL where all the traffic was.

Host: r1---sn-vox-n32e.c.android.clients.google.com

Even if some updates happened there is no way so much traffic was spent. I don't have that many applications. Does anyone have idea what this url is or where can I ask for more information.

Thank you in advance