I've caught this system app connecting to the internet on behalf of some proprietary apps. Here is an example of a site it connects to:
call.whatsapp.com
v.whatsapp.com.
There are other addresses like google servers.
A quick search reveals that this is some security system against dangerous permissions implemented by google and apparently present in AOSP and Graphene too.
https://fixyourandroid.com/about/intent-filter-verification-service-app/
It is a system app and cannot be disabled. What got me worried is that third party apps can use it to access internet. Is this behavior safe or can it compromise privacy?