N.Y. State Fin. Law § 152

§ 152. Conditions of sale. At a sale under such foreclosure the\ncomptroller shall require the purchaser to pay, at the time of the sale,\nthe costs and expenses thereof, and at least one-fourth of the amount so\nunpaid; and for securing the remainder of the moneys due the state, on\nthe execution of a deed or of the affidavits of sale to the purchaser,\nhe may accept from the purchaser a bond and mortgage to the state on the\npremises sold, payable in six equal annual instalments, with annual\ninterest at six per centum. If the mortgaged premises sell for a greater\nsum than the amount so unpaid and the costs and expenses of the sale,\nthe comptroller shall also require the purchaser at the time of the sale\nto make payment of such surplus. The expense incurred by the\nattorney-general in any action or proceeding for the foreclosure of any\nsuch mortgage, shall be paid to him out of the treasury.\n