Was 株式会社ミヤキ hit by ransomware?

株式会社ミヤキ was listed by the Cicada3301 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 Cicada3301 ransomware group?

Cicada3301 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 株式会社ミヤキ breach?

Cicada3301 published data attributed to 株式会社ミヤキ. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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株式会社ミヤキ

Claimed by Cicada3301 · listed 2 years ago

22m

Age

since listed · data leaked

Status timeline

ListedSep 9, 2024
Data leakeddate unknown

At a glance

Group: Cicada3301
Status: Data leaked
Country: Japan
Sector: Manufacturing
Listed on leak site: Sep 9, 2024

About the victim

AI dossier — public-source company profile

株式会社ミヤキ (Miyaki Co., Ltd.) is a Japanese manufacturer specializing in advanced surface treatment technologies, particularly the proprietary Kashima Coat® technology. The company produces hard-anodized aluminum coatings and anti-corrosion treatments, including work on difficult-to-anodize materials and aluminum die castings.

Industry: Specialty Coatings & Metal Treatment

Attack summary

Severity: high — Confirmed exfiltration of proprietary R&D materials and trade secrets for specialty coating technology; threat of public release indicates data is held hostage; loss of competitive advantage in niche industrial technology represents significant business harm.

The cicada3301 group claims to have exfiltrated research materials and proprietary product documentation including formulations for Kashima Coat®, hard anodized aluminum, and anti-corrosion aluminum treatments. The group threatens imminent data release if contact is not established.

high

Data the group says was taken

AI dossier — extracted from the leak post

product research materials
Kashima Coat® formulation/specifications
hard anodized aluminum specifications
anti-corrosion coating research
proprietary coating technology documentation

What the group claims

Manufacturing of "Kashima Coat®", a unique technology in the world; Also compatible with difficult-to-anodize materials; Anodizing of aluminum die castings; Standard production of hard anodized aluminum, which boasts industry-leading standards. We have downloaded all the research materials of the company's products such as anti-corrosion aluminum, Kashima coating , hard anti-corrosion aluminum, etc. Data will be released soon if the company doesn't contact us!

Sources

Victim sitekashima-coat.com
Leak posthttp://cicadabv7vicyvgz5khl7v2x5yygcgow7ryy6yppwmxii4eoobdaztqd.onion/1v7ni09utolyie44zotqu6ndl9whfxnm

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 Cicada3301

Cicada3301 is a recently emerged ransomware group that began operations in June 2024, primarily motivated by financial gain through extortion activities targeting organizations across multiple sectors. The group's origin and affiliations remain largely undocumented in public threat intelligence reporting, with limited information available regarding their operational structure or potential connections to other cybercriminal organizations. Based on observed targeting patterns, Cicada3301 has demonstrated a preference for attacking business services, technology, manufacturing, and financial sector organizations, with their operations concentrated primarily in English-speaking countries including the United States, United Kingdom, and Canada, as well as extending to Spain and Singapore. The group has successfully compromised approximately 75 known victims since their emergence, though specific details regarding their attack methodologies, initial access vectors, encryption techniques, and extortion tactics have not been extensively documented in publicly available threat intelligence reports from major cybersecurity firms or government agencies. Given the limited public documentation available from CISA, FBI, Mandiant, or other reputable security researchers, the group's current operational status, technical capabilities, and specific attack infrastructure remain largely uncharacterized in open-source intelligence reporting. As of the most recent observations, Cicada3301 appears to remain active in conducting ransomware operations, though comprehensive analysis of their tactics, techniques, and procedures awaits more detailed public reporting from established threat intelligence sources. The group has been linked to 75 public disclosures across our corpus. First observed on a leak site on June 20, 2024; most recent post September 4, 2025. The operation is currently inactive.

Timeline of this disclosure

September 9, 2024株式会社ミヤキ listed by Cicada3301on the group's public leak site

Other recent disclosures by Cicada3301

Cicada3301 has been linked to 75 public victims on Darkfield. A sample of the most recent:

See the full Cicada3301 dossier →

Sector and geography

This disclosure adds to ransomware activity in the Manufacturing sector, which has 3,681 disclosures indexed across all operators we track. Geographically, 株式会社ミヤキ is reported in Japan, a country with 88 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Cicada3301 means 株式会社ミヤキ 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 Cicada3301'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.