Its the scam from the IRS.  On your phone th spoof an actual IRS number.

IRS fraud. middle eastern subject claiming to be an IRS agent.  have some fun with them and they get really mad.

Scam caller, says he will send sheriff, called sheriff and they have had various same complaints. I called Office David back, says he is IRS Officer, Ha, not true! I told him to give me his address and I will go discuss this issue and he hung up on me.
714-588-1604

Cell phone caller (703.622.8330) informs my voice mail in very broken English she is from IRS.  I have "tax fraud" problem, the details I can get by calling 714.581.6049.  If I don't call immediately they will take me to local justice center to be arrested.  What a joke!!  Just another out-of-country IRS scam.  Tragically, some folks fall for this stuff.

I got this message that the IRS was filing a lawsuit for tax evasion.  And was told to call 714-581-6049 or they would sent the sheriff to arrest me.  I had received a similar call last year.  I reported both to the www.TIGTA.GOV.