They are "phishing" for your personal information. If you bite they will get into your accounts and get any money you have. Also, they send you a check for more money then you ask for. You deposit the check and then send the extra amount to their account via Western Union. Of course you can keep a little extra for your troubles. Days later when the banks attempts to clear the check, it bounces sky high. You are now liable for the money that you sent back to them and they keep your cash.
These scams go on day after day. It costs these knuckleheads next to nothing to put out there. If they get one person to respond, they make money. They operate outside of The United States so there is little law enforcement can do except educate the public.