Company

Otsuka Corporation

Otsuka Corporation (Chiyoda, Tokyo; Information and communications) appears in 2 related cybersecurity incidents. The latest was disclosed on 2024-06-18.

Profile

Industry/type: Information and communications
Location: Tokyo, Chiyoda
Listing: TSE 4768
Website: https://www.otsuka-shokai.co.jp/

Public figures

Employees8,287Non-consolidated2025-12-31
METI: Gビズインフォ
Revenue¥1.2TNon-consolidated2025-12-31
METI: Gビズインフォ
Capital¥10.4BNon-consolidated2025-12-31
METI: Gビズインフォ

Metric	Value		As of	Source
Employees	8,287	Non-consolidated	2025-12-31	METI: Gビズインフォ
Revenue	¥1.2T	Non-consolidated	2025-12-31	METI: Gビズインフォ
Capital	¥10.4B	Non-consolidated	2025-12-31	METI: Gビズインフォ

Incident history

Disclosed 2024-06-18Updated 2026-10-23Fukui, Tokyo[Contained][Severity: Critical][Through a supplier][Major]
Shirasaki: ransomware; Otsuka Corporation's customer data may also have leaked
[Ransomware][Service outage][Data leak]Leaked 8.4KOrganizations 2
Disclosed 2024-04-19Updated 2026-10-23Tokyo[Contained][Severity: Moderate][Breached][Moderate]
Otsuka: email sent to the wrong address leaked names of 2,687 customers
[Misdelivery][Data leak]Leaked 2.7KOrganizations 1

		Incident	Role	Impact level				Methods	Impacts		Status
2024-06-18	2026-10-23	Shirasaki: ransomware; Otsuka Corporation's customer data may also have leaked	[Through a supplier]	[Major]	[Critical]	2 Shirasaki Corporation, Otsuka Corporation	Fukui, Tokyo	[Ransomware]	[Service outage][Data leak]	8,436	[Contained]
2024-04-19	2026-10-23	Otsuka: email sent to the wrong address leaked names of 2,687 customers	[Breached]	[Moderate]	[Moderate]	1 Otsuka Corporation	Tokyo	[Misdelivery]	[Data leak]	2,687	[Contained]