It's scammers. They are trying to engage in wire transfer / check fraud. Where they pay more than something's worth to get you to wire them the remaining balance. Their check is obviously fake and the bank it is supposedly drawn on is immediately able to recognize the check as being a fake. They were hoping for you to deposit at an ATM and then wire them a balance back. It's ridiculous. Has been going around forever. They still don't learn but there are enough useful idiots that will follow through. Similar to the Nigerian scams the various news programs have covered. Stay away! Don't answer! Block and report!