NikkeiGoogle Workspace / Microsoft 365

1MinorPossibleAnnounced

Unauthorized logins to Google Workspace may have exposed names and emails of 1,646 people. A separate Microsoft 365 breach may also have exposed some email bodies; the scope is under investigation.

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
Media & publishing
Operational impact
None

Data involved

DataStatusCountGroupEvidence
Email addressPossible leakNot disclosed—Source(opens in a new tab)
NamePossible leak1,646 people—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. 不正ログインによる情報漏洩についてwww.nikkei.co.jp · Published 2026-10-04(opens in a new tab)
  2. サイバー攻撃による情報漏洩、不審メールの送信についてwww.nikkei.co.jp · Published 2026-10-04(opens in a new tab)