Three brothers in San Francisco discovered an original first edition copy of Superman No. 1 from 1939 while cleaning out their late mother's attic.The comic was graded 9.0 by the Certified Guaranty Company and sold at Heritage Auctions for a record $9.12 million, making it the most expensive comic book ever sold.The buyer remains anonymous, and the auction highlights the cultural and financial significance of Superman as a DC intellectual property.