There have been news reports that scammers are setting up false identities for your telephone caller ID.
So when the scammer calls your phone will say “IRS” or “Credit Bureau” or “First National Bank” or some other legitimate organization.
Best bet – let all such calls go to voice mail, listen to the message and then decide if this is someone you should talk to.
If you get on the phone with any suspicious, ask for a call back number of make up an excuse to hang up.
Again, the IRS will not contact you via phone. And no, you did not win the Australian Lottery.