strace, netstat or tcpdump to identify unknown network activity and program

I've been trying to uncover the origin of some network calls, specifically to ip addresss associated with bc.googleusercontent.com

I'm a bit curious why this network activity only happens when using Firefox and from what I've read googleusercontent.com is reported as both a service for individuals outside the google ecosphere for private businesses, etc., as well as being used by google itself.

Using tcpdump on my network adapter and filtering with grep for bc.googlecontent.com isolates the activity, but now I need to dig deeper and find out what service/program etc. is activating these calls.

Strace was recommended, however, it needs the PID which I can't get on a per connection basis or if it happens it's gone quickly so unable to see it. Is there some way to use strace so that it will do the necessary filtering upfront, thereby eliminating all the other activity or better, another linux program I can use to immediately get the name of the program making these connections.

Thank you.