If they have any snap, they will have locked down that Wi-Fi access point
to allow only devices with IP X or MAC address Y.
( Or both )
Along with a fairly lengthy WPA key.

They can also ( depending on the router ) limit any
outside net access to particular devices only, during
specific times of day, or disallow it all together.

If their IT folks are watching the firewall, they will be able to spot your NIC card
pretty quickly since it will stand out like a Christian in Iran

Don't get fired over something like this