Apartment app operator reports phone-number leak from October exports

The operator of the apartment living platform Apartment notified users on November 6, 2026 that some of their mobile phone numbers had been leaked after an attacker made unauthorized use of the service's data export function, according to dailysecu.com.

The operator said the attacker accessed the export function twice on October 23, 2026, at 10:36 AM and again at 2:41 PM, and that files containing some users' mobile phone numbers were taken out of the system. The breach was only detected on November 4, 2026 at 2:00 PM, roughly 12 days and 3 hours after the first export.

The operator said the exported files held mobile phone numbers only. Names, apartment names, unit numbers, resident registration numbers, account passwords and payment or financial information were not included, it said.

After detecting the incident, the operator blocked the attacking IP addresses, reset administrator accounts and reported the case to the Korea Internet & Security Agency (KISA) and the police. It said it would suspend operation of vulnerable web pages until the third week of November 2026.

The operator has not disclosed how many users were affected or the size of the exported files. As of June 2026, Apartment's official website listed more than 4,300 contracted complexes, over 3.6 million sign-ups and over 2.56 million monthly active users; the platform offers apartment notices, maintenance fee checks, electronic voting, community facility reservations, visitor vehicle registration and shared entrance access.