As has been stated, good or bad, svchost.exe is a fundamental part of the Windows OS and will probably need some Internet access. As an example, and by default, svchost is used by Windows, in the following situations:
DHCP Client (Dynamic Host Configuration Protocol)
When your PC connects to the Internet it is given an IP Address by your ISP and is subsequentially updated at specific periods.
DNS Client (Domain Name System)
When you need to access a page on the Internet the name of the page needs to be resolved to an IP Address.
ERSvc (Error Reporting Service)
Reports system and application faults to Microsoft
Win32Time (Windows Time Synchronisation)
If you synchronise your PC clock with an Internet source.
Windows Automatic Updates
There are others...