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Cyber Threat
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Ransomware victim Manufacturing

KOIKE Sanso Kogoyo Co. Ltd.

Listed by Exitium on · organisation based in Japan

Disclosed
Oct 10, 2026
Leak-site listing date
Threat group
Exitium
5 victims listed
Country
Japan
#11 most targeted
Sector
Manufacturing

ThreatAI analysis

Compiled from this incident record and the threat intelligence profile for Exitium. Figures and technique mappings are quoted from the source data, not inferred.

Exitium named KOIKE Sanso Kogoyo Co. Ltd., based in Japan's Manufacturing sector, on its dark web leak site on 10 October 2026.

About the Exitium group

Exitium is a data extortion group first observed in early 2026, operating a Tor-based double extortion site and targeting victims via bulk data exfiltration followed by public naming-and-shaming, with known victims including a Brazilian agro-industrial firm and a US county appraisal district. Exitium has listed 4 victims since March 2026.

Incident analysis

KOIKE Sanso Kogoyo Co. Ltd. was listed by Exitium ransomware, a group with 5 victims recorded in this database. The listing appeared on the group's leak site on October 10, 2026.

KOIKE Sanso Kogoyo Co. Ltd. is based in Japan and operates in the Manufacturing sector. Japan ranks #11 worldwide for ransomware disclosures, with 294 victims in this database.

Sector context. Manufacturing companies are frequently targeted because production downtime directly translates to financial loss. Ransomware operators exploit this time-sensitivity to demand higher ransoms and faster payment.

Exitium typically follows a double extortion model: data is exfiltrated from the victim's systems before files are encrypted, so the victim faces two demands at once — pay to restore access, and pay to keep stolen data unpublished. The leak site, where this listing appeared, is the lever for the second demand.

Source. Public leak-site disclosures aggregated via the ransomware.live API. The disclosure date is when the listing was published, which can differ from the date of compromise. This site does not publish or link to stolen data. Last updated .

Frequently asked questions

Was KOIKE Sanso Kogoyo Co. Ltd. attacked by ransomware?

Yes. KOIKE Sanso Kogoyo Co. Ltd. was listed as a victim of the Exitium ransomware group on October 10, 2026. The organisation is based in Japan and operates in the Manufacturing sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked KOIKE Sanso Kogoyo Co. Ltd.?

KOIKE Sanso Kogoyo Co. Ltd. was attacked by Exitium ransomware. Exitium is one of the most active ransomware groups, having claimed 5 victims globally. The group typically employs a double-extortion model: encrypting the victim's files and threatening to publish stolen data.

When did the KOIKE Sanso Kogoyo Co. Ltd. ransomware attack occur?

The ransomware attack on KOIKE Sanso Kogoyo Co. Ltd. was disclosed on October 10, 2026. This date reflects when the victim was published on the threat group's leak site, which may differ from the actual date of initial compromise.

What data was stolen in the KOIKE Sanso Kogoyo Co. Ltd. ransomware attack?

The specific data stolen from KOIKE Sanso Kogoyo Co. Ltd. has not been independently verified by this platform. Ransomware groups typically exfiltrate data before encrypting systems and use the threat of publication to pressure victims. As a Manufacturing organisation, KOIKE Sanso Kogoyo Co. Ltd. likely held sensitive business data, client information, and operational records.

How can organisations protect against Exitium attacks?

To defend against Exitium and similar threat actors, organisations should: maintain regular offline backups tested for restoration; implement network segmentation to limit lateral movement; deploy multi-factor authentication on all remote access; use endpoint detection and response (EDR) tools; conduct regular phishing and security awareness training; and monitor threat intelligence feeds for indicators of compromise (IOCs) associated with active groups.