Don't know who this is, but this number and variations of, with different area codes in Illinois, call from time to time, never leaving a message.

I've called back and usually reach someone who is completely in the dark about their number calling mine, which leads me to believe that whoever is calling is spoofing the numbers of completely innocent people.

Other spoofed numbers using this variation are:

217-331-8902
224-331-8902
224-331-8905
309-331-8902
309-331-8905
331-331-8902
331-331-8905
708-331-8902
708-331-8905