Got a call from this number too. Left partial message saying I'm being sued by the IRS and no further information other than call them back at this number.
I knew it was a scam when I heard that the IRS had filed a claim against me when I knew that wasn't true. As a matter of fact I got this call twice and knew what was coming the second time, so I immediately hung up.
They called me twice yesterday, i Didn't answer and they left a partial message informing me that I was being sued by the IRS and to call them back immediately. They started calling me back today 7AM sharp. I'm about to block the number