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JAENES
BPossible leakOctober 9, 2026 announced

越後天然ガス（両毛システムズ利用）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
October 9, 2026
Severity
BIncidents centered on names and contact details.
Scale
1,000 records
Main impact
It was announced that a ransomware attack on 両毛システムズ may have led to the leak of approximately 1,000 customer records of 越後天然ガス.
Information involved
User / member IDCard & payment dataHome addressFull name
Cause / key point
The cause is under investigation.About Ransomware
Industry
Services & other
Listing / capital
Unlisted
Sources
Last updated
October 20, 2026
User / member IDCard & payment dataHome addressFull nameHow severity is assessed →

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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: Ransomware(Encrypting data and demanding a ransom)

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