Some international students in the U.S. have been sent the stimulus check or received a direct deposit because they erroneously filed the wrong tax form. This most frequently occurs when student use a software service like TurboTax, which cannot be used by non-residents (as defined by the IRS).
If this scenario applies to you, it is important to know that you cannot keep the money. You will need to file an amended tax return with the correct form and return the stimulus money. Instructions for filing an amended tax return are attached to this email. Instructions for returning the stimulus money can be found here.