Received the same call. They a claiming IRS is filing a law suit against me. Called back the number. Talked with a guy who was difficult to understand. Claimed he was the IRS. I then hung up. I am currently trying to report the number to the REAL IRS.
Got a message from this number twice posting as IRS and telling us that it's a final notice and they are filing a law suit against us. Called the number back using a different phone number and no one answer, just a noise sound in the background.