Caller: Claimed to be 'NBN'

An Indian 'gentleman' with the name 'John Wilson' (Red flag already there!) claiming to be from NBN called me, and very quickly got rude when I expressed some disbelief that NBN would be calling me at all. Tried to tell me there was a 'security problem'. The rest of the script would normally be trying to get me to install teamviewer or similar so they can remotely access my computer/ipad/whatever I might have, in order to steal my data.