I got the same message Sunday night which was unusual that the IRS would call me on a Sunday night. I followed up with the IRS Monday and they have no knowledge of that phone number so yes it is a scam!!
Got a call this morning from 716-980-5039 seemed like a pre-recorded message. Message said from an IRS officer named Adam Scott asked to call back to the aforementioned number. This person has a thick foreign Indian accent. DO NOT CALL BACK. IT IS A SCAM.
Same no. Same message but Russian accent. When I said IRS can't call at 6:45 in morning he said "listen Buddy". That was my clue I said "f u" and hung up.