Was Matusima hit by ransomware?

Matusima was listed by the 8Base ransomware operation (Japan), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the 8Base ransomware group?

8Base is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the Matusima breach?

8Base published data attributed to Matusima. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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株式会社マツシマ (Matsushima Corporation)

listed as Matusima · Claimed by 8Base · listed 2 years ago

25m

Age

since listed · data leaked

Status timeline

ListedMay 27, 2024
Data leakeddate unknown

At a glance

Group: 8Base
Status: Data leaked
Country: Japan
Listed on leak site: May 27, 2024

About the victim

AI dossier — public-source company profile

Matsushima Corporation is a Japanese machinery and equipment distributor based in Nagano Prefecture, operating since at least the mid-20th century. They sell, maintain, and rent agricultural machinery, construction equipment, vehicles, HVAC systems, plumbing/heating equipment, and solar energy systems with battery storage. They also provide home renovation services.

Industry: Agricultural & Construction Machinery Sales, Maintenance & Rental; HVAC Systems; Solar Energy & Battery Systems; Home Renovation
Address: 〒399-4601 長野県上伊那郡箕輪町松島8750 (8750 Matsushima, Minowa Town, Kami-ina District, Nagano Prefecture 399-4601, Japan)

Attack summary

Severity: medium — Data has been published by the group, and the victim is a real operating business with customer/operational records at risk. However, no specific regulated data (PII at scale, financial records, medical data) is explicitly mentioned, and no proof files/screenshots are advertised in the post.

8Base claims to have accessed Matsushima Corporation's systems and published exfiltrated data. The specific data categories and operational impact are not detailed in the available leak post.

medium

Data the group says was taken

AI dossier — extracted from the leak post

Business records
Corporate systems data

What the group claims

Matusima Corporation is engaged in the Sale and maintenance of agricultural machinery/general purpose machinery, Distributoragricultural machinery, Sale and maintenance of construction machinery, Piping/plumbing equipment, mechanical equipment, Heating and cooling, water supply and sewerage, air conditioning, septic tank, water supply and sewerage, construction of mechanical equipment, design and construction, rental of construction equipment. Sale and maintenance of cars, Sale and construction of solar energy production systems/, batteries https://www.matusima.com

Sources

Victim sitematusima.com
Leak posthttp://xb6q2aggycmlcrjtbjendcnnwpmmwbosqaugxsqb4nx6cmod3emy7sad.onion/company/7890454

Source

Indexed 2 years ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.

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Disclosure context

About 8Base

8Base is a ransomware group that emerged in May 2023, operating with primarily financial motivations and demonstrating a rapid escalation in activity with 458 documented victims across multiple sectors. The group's origin and specific affiliations remain largely undocumented by major security agencies, though their operational patterns suggest they function as an independent ransomware operation targeting predominantly Western markets. Based on publicly available victim data, 8Base appears to focus on opportunistic attacks against business services and manufacturing sectors, with the United States representing their primary target geography, followed by France, Brazil, Italy, and the United Kingdom, indicating a preference for developed economies with established digital infrastructure. The group has notably impacted healthcare and technology sectors alongside their primary business services focus, suggesting a broad targeting approach rather than sector-specific specialization. Given the group's recent emergence in 2023 and continued victim accumulation across diverse geographic and sectoral targets, 8Base appears to remain active as of current reporting periods, though detailed technical methodologies, specific attack vectors, and notable high-profile campaigns have not been extensively documented in public threat intelligence reporting from major security agencies. The group has been linked to 458 public disclosures across our corpus. First observed on a leak site on May 23, 2023; most recent post February 1, 2025. The operation is currently inactive.

Timeline of this disclosure

May 27, 2024Matusima listed by 8Baseon the group's public leak site

Other recent disclosures by 8Base

8Base has been linked to 458 public victims on Darkfield. A sample of the most recent:

See the full 8Base dossier →

Sector and geography

Geographically, Matusima is reported in Japan, a country with 220 ransomware disclosures in our corpus.

If your organisation is affected

A listing by 8Base means Matusima appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
Report the incident to your national CERT, JPCERT/CC (Japan), as required for your jurisdiction.
Monitor for the data appearing on 8Base's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.