HiHoBiZiMo / Hikari Giga

2LowPartly confirmedAnnounced

A third party used information gathered by phone to impersonate users and log into customer pages of BiZiMo, Hikari Giga and other services. It affects 38,509 contracts.

This incident was imported from a dataset that compiles public announcements, and we are still checking it against the sources. Counts and causes will be updated after the check. Sources are in Japanese.

Cause
Account takeover
Sector
IT, cloud & telecom
Operational impact
None

Data involved

DataStatusCountGroupEvidence
NameLeak confirmed38,509 accounts—Source(opens in a new tab)
Postal addressLeak confirmed38,509 accounts—Source(opens in a new tab)
Phone numberLeak confirmed38,509 accounts—Source(opens in a new tab)
Email addressLeak confirmed38,509 accounts—Source(opens in a new tab)

Counts are the figures the organization announced. Because the same person may be counted more than once, we do not add the rows together.

What users should do

  • Watch for emails and texts pretending to be the company

General steps based on the type of data involved. Check the organization’s notice or help line to see whether you are affected.

Tools for this kind of attack

Picked from the cause of the incident: tools that help you check your own systems for the same kind of weakness, or spot the warning signs.

Wazuh

Impact Local only
wazuh/wazuh

A free security platform (SIEM/XDR) that collects logs, configuration, and vulnerability data from agents on your endpoints and shows it all in one dashboard.

Purpose
Defense
Type
Self-hosted server
Difficulty
Advanced
License
CopyleftGPL-2.0(一部の構成要素は Apache-2.0)
Category
Vulnerability scanning / Forensics
Actively updatedstars17,410Last update 2026-10-24
Read the Wazuh review

Sources

  1. 〖重要なお知らせ〗お客様情報への第三者によるアクセスが確認された事案に関するご報告 - BiZiMo 光 公式サイトbizimo.ne.jp · Published 2026-10-08(opens in a new tab)