Daiwa SecuritiesInquiry management

3MediumPossibleAnnounced Updated

Unauthorized login to the FAQ system of a contractor may have exposed names, emails and securities account numbers of about 110,000 Daiwa customers who made inquiries.

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
Via a vendor or service, Account takeover
Occurred
2026-10-02 – 2026-10-03
Sector
Finance & insurance
Operational impact
None

Data involved

DataStatusCountGroupEvidence
Email addressPossible leakabout 110,000 people—Source(opens in a new tab)
Payment detailsPossible leakabout 110,000 people—Source(opens in a new tab)
NamePossible leakabout 110,000 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

  • Check your card statements
  • 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. 大和証券:外部委託先への不正アクセスによるお客様情報の漏洩の可能性ssl4.eir-parts.net · Published 2026-10-05(opens in a new tab)
  2. スカラコミュニケーションズ:FAQシステムi-askへの不正アクセスscala-com.jp · Published 2026-10-06(opens in a new tab)
  3. 【大和証券との包括的業務提携】大和証券の外部委託先への不正アクセスによるお客さま情報の漏洩の可能性についてwww.iwatebank.co.jp · Published 2026-10-06(opens in a new tab)