> JapanHacked_
[Investigating][Severity: Major][Intrusion]

M3: unauthorized access to the MR-kun service for drug makers

On 15 October, M3 said unauthorized access to the system of MR-kun, its service for pharmaceutical companies, leaked personal data of physician members and drug company staff. Fewer than 10% of all physician members and several hundred drug company staff are affected; names, workplaces and, for some, email addresses were included. The exact number is still being checked. Login passwords and m3 points were not included.

Disclosed

2026-10-15

Organizations involved

1

Leaked or at risk

Unknown

Downtime

Unknown

Timeline

  1. Disclosed 2026-10-15
  2. 1 days

Attack or cause

Method
[Intrusion]
Impact
[Data leak]
Entry point
Unknown

Data exposed or at risk

[Name][E-mail address][Employment]

Services hit

Organizations involved

Open in organization search

Sources

  1. [1][News]医師の氏名や勤務先などが漏えい エムスリーに不正アクセスASCII.jp · 2026-10-16
  2. [2][News]エムスリーが個人情報漏洩 製薬向けサービスに不正アクセスNikkei · 2026-10-15