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JAENES
APossible leakSeptember 28, 2026 announced

大東ガス株式会社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
Unconfirmed
Announced on
September 28, 2026
Severity
AFinancial and HR records — information that easily translates into monetary damage.
Scale
124,000 records
Main impact
It was announced that files left on the contractor's internal network were illegally accessed, and approximately 124,000 customer records may have been exposed.
Information involved
User / member IDPhone numberHome addressFull name
Cause / key point
The cause is under investigation.About Supply chain attacks (via vendors & shared services)
Industry
Services & other
Listing / capital
Unlisted
Sources
Last updated
October 20, 2026
User / member IDPhone numberHome addressFull nameHow severity is assessed →

Is this incident worth paying attention to?

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: Supply chain attacks (via vendors & shared services)(Compromising the provider instead of the user)

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