and ST HD: unauthorized access to business servers
From about 7:30 on October 22, an outside attacker attempted logins to, broke into and extracted data from several business servers; the company detected the activity at about 10:00, isolated the servers, cut the access route by 17:00 and stopped internal business systems. Data on about 2.5 million customers (names, birth dates, genders, addresses, phone numbers, emails and member IDs) and about 10,000 business partners may have leaked; the scope for employees was being checked. Payment data and passwords are not included. Stores and the web store stayed open, but member points could not be used.
Disclosed
2026-10-23
Organizations involved
1
Leaked or at risk
2.5M
2,500,000
Downtime
Unknown
Timeline
- Started, Detected 2026-10-22
- Disclosed 2026-10-23
- 1 days
Attack or cause
- Method
- [Intrusion]
- Impact
- [Data leak][Service outage]
- Entry point
- Unknown
Data exposed or at risk
Organizations involved
[Breached][Critical]Ibaraki, MitoWholesale and retail trade2,500,000 leaked
and ST HD Co., Ltd.
Sources
- [1][Official]当社業務サーバーへの不正アクセスの発生および個人情報等流出の可能性に関するお詫びとお知らせand ST HD · 2026-10-23
- [2][News]アンドエスティHD、情報流出か 氏名、住所など250万件Kyodo News · 2026-10-23