Gmarket reported to KISA on October 30 that some customers’ e-coupon PINs had apparently been registered or redeemed by third parties without authorization. The company says it blocked the unauthorized access route, completed emergency security measures and plans compensation for confirmed losses. The cause and scope remain under investigation; the report does not establish a breach of all accounts or payment details. Customers should review their coupons’ redemption history and follow official investigation and compensation notices.