Windows 10 computer waking up from sleep

This is a known VirtualBox bug: Ticket #18549 : Windows host wakes from standby mode constantly.

The bug was marked as fixed about 5 months ago, so should be included in the latest version VirtualBox 6.0.14, released October 15 2019. (Actually it should have already been in some release even sooner than that.)

I suggest refreshing your VirtualBox version. If the problem is not fixed, you could ask to re-open that bug-report, and use Albin's solution in the meantime (although it might be a bit too strong).

It doesn't look like the (any) network card is waking your computer but the Wake Timer in Windows 10. You can disable them globally, see here and here.

For example open power options and choose "disable":

But I'm not sure how this connects to VBoxSVC.exe. However I would try to disable them and see if this resolves the issue first.