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JAENES
BPossible leakOctober 23, 2026 announced

アンドエスティHD（グループ業務サーバー）Data breach / unauthorized access incident

笹尾 祐太朗の写真Reviewed by Yutaro SasaoWritten by Leak Watch editorial team published ・ updated
Occurred on
October 22, 2026
Announced on
October 23, 2026
Severity
BIncidents centered on names and contact details.
Scale
2,500,000 records
Main impact
They disclosed that unauthorized access to business servers may have exposed about 2,500,000 customers (name, date of birth, gender, address, phone number, email address, member ID), about 10,000 business partners (company name, address, contact person name, phone number, email address), and employee information (scope under investigation). Payment information such as credit card details and user-set passwords are not included; stores and the web store will continue operating but member points are unavailable, and they consulted the police and reported to the Personal Information Protection Commission on October 23.
Information involved
Full nameDate of birthHome addressPhone numberEmail addressUser / member ID
Cause / key point
Unauthorized external access leading to intrusion into multiple servers and data extraction (occurred around 2026-10-22 at 7:30 AM and was detected and isolated around 10:00 AM the same day).
Industry
Retail & e-commerce
Listing / capital
Listed companyTSE Prime 2685(アンドエスティHD)
Sources
Last updated
October 29, 2026

Stock price reaction to the disclosureアンドエスティHD / 東証プライム 2685

2026.10.03 〜 2026.10.29Loading…

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Written & reviewed

笹尾 祐太朗の写真

Reviewed byYutaro SasaoFounder & CEO, MediaLeap Inc.

CEO of MediaLeap Inc. Working on both sides of web advertising and web media since 2013; founded the company in May 2025.

Review scope: cross-checking against primary sources (official and government announcements), verifying claims stay within the facts, and checking source attribution。Last reviewed:

Written by:Leak Watch editorial team (AI-assisted drafts verified against sources by the editorial team) · Reviewer profile · Request a correction

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Attack method classification: Unauthorized access (method undisclosed)(Breached, but the technique was not identified or disclosed)

Read the Unauthorized access (method undisclosed) guide and national trends →

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