N.Y. Aband. Prop. Law § 202
There may be made parties to such action, all persons who would have, might have or might claim to have any interest in or lien upon the premises so escheated or forfeited, at the time of such escheat or forfeiture, and all persons in possession of such real property. Where the names of the defendants are unknown, they may be designated as "unknown defendants." The provisions of law applicable to actions to recover real property shall apply to such actions, except that service of the summons shall not be deemed to be complete until, pursuant to an order of the court, the summons together with a notice directed to the defendants setting forth the object of the action, a brief description of the land affected, the source and manner in and by which it is alleged that said real property shall have escheated or forfeited to the people, and the name or names of person or persons whose title or interest shall have so escheated or have been forfeited, shall have been published once in each week for four successive weeks in two newspapers designated in the order for such publication as most likely to give notice to the defendants to be served.
N.Y. Aband. Prop.Law § 202