Caller: Someone acting on behalf of the Australian Tax Office (bot)

The automatic voice (bot) on the other end said this was my last notice to respond to a tax violation that's been reported, and if I didn't respond right away, action would be taken (such as potential arrest).
This is the first I have heard of a tax violation by any means, and seemed to be a crank call (I hope). I hung up without pressing any of the requested buttons. It didn't seem legit at all, as I have not been notified of a tax violation or been sent any correspondence from the ATO directly.
I would say this is a scam whereby people "opt in" by pressing the keypad. Don't press, just hang up.