2025 Daesung Educational Development Institute — student PII intrusion (Jul)
Data compromised
Names, mobile numbers, emails, IDs, dates of birth, addresses (per institute notice)
Technical writeup
Daesung Educational Development Institute (대성학력개발연구소), an affiliate of the Daesung Academy education group, notified members that an unauthorized third party accessed internal systems on 18 July 2025 (about 14:00–14:30 KST) and reached personal-information files. MTN and other Korean education-sector reporting said exposed fields included names, mobile numbers, email addresses, IDs, dates of birth, and addresses. The institute did not publish an attested victim count in the notices summarized by trade press; members were warned about phishing and smishing risk. Company-confirmed intrusion; count unpublished.
Root cause
Unauthorized access to internal systems (method not publicly detailed)