Security risk and back door access for USB netowrk devices

I have a site wide issue were users can access the internet using USB Modems
/ Network cards.

I want to disable to capability due to some recent security treat that
entered our network. All PCs use USB K/K and mice there fore disabling UBS is
not an option.

I believe doing some work on IPSEC can resolve this issue but I cannot
figure it out..

Please advice.
Thanks..
I have a site wide issue were users can access the internet using USB Modems
/ Network cards.

I want to disabel to capability due to some recent security treat that
entered our network. All PCs use USB K/K and mice there fore disabling UBS is
not an option.

I beleive doing some work on IPSEC can resolve this issue but I cannot
figure it out..

Please advice.
thanks..

Richie Smith
.