Disclosure context

About coinbasecartel

CoinbaseCartel is a ransomware group that emerged in September 2025 with financially motivated operations targeting organizations across multiple sectors and geographic regions. The group has demonstrated significant activity in a short timeframe, compromising at least 102 known victims primarily across the United States, United Arab Emirates, Germany, Canada, and Brazil. Their targeting patterns show a preference for technology companies, financial services organizations, manufacturing entities, and consumer services businesses, suggesting an opportunistic approach focused on organizations likely to have both valuable data and the financial resources to pay ransoms. Given the group's recent emergence and limited public documentation from established threat intelligence sources, details regarding their specific attack methodologies, infrastructure, and organizational structure remain largely unconfirmed by major cybersecurity firms or law enforcement agencies. The group appears to maintain active operations as of late 2025, though comprehensive analysis of their tactics, techniques, and procedures awaits further investigation and reporting by established threat intelligence organizations. The group has been linked to 176 public disclosures across our corpus. First observed on a leak site on September 15, 2025; most recent post May 16, 2026. The operation is currently active.

Also tracked as: coinbase cartel.

Timeline of this disclosure

May 14, 2026Rogiken / Institute of Science Tokyo listed by coinbasecartelon the group's public leak site

Data size: 43 GB

Sector and geography

This disclosure adds to ransomware activity in the Education/Research sector. Geographically, Rogiken / Institute of Science Tokyo is reported in Japan, a country with 108 ransomware disclosures in our corpus.

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.

Ransomware victim disclosure

← All victims

Institute of Science Tokyo

listed as Rogiken / Institute of Science Tokyo · Claimed by coinbasecartel · listed 7 days ago

43 GB

Data size

Age

since listed · listed for ransom

Status timeline

Listed
May 14, 2026

Current state: Listed for ransom

At a glance

Group: coinbasecartel
Status: Listed for ransom
Country: Japan
Sector: Education/Research
Listed on leak site: May 14, 2026
Data size: 43 GB

About the victim

AI dossier — public-source company profile

Institute of Science Tokyo (formerly Tokyo Institute of Technology and Tokyo Medical and Dental University, merged in 2024) is a major Japanese national research university located in Tokyo, Japan. It conducts advanced research and education across science, engineering, and medicine. It is one of Japan's leading research institutions with thousands of students and faculty.

Industry: Higher Education & Scientific Research
Founded: 2024

Attack summary

Severity: medium — The victim is a major national research university with significant research data; however, no specific data has been described or proof published for this particular victim — it is listed alongside others with a vague promise of future disclosure, warranting medium rather than high severity.

The coinbasecartel group claims to have exfiltrated data from Rogiken / Institute of Science Tokyo and lists it among multiple victims, with no specific data type or volume described for this victim. No proof files or samples have been published for this victim as of the listing; the post notes the group will 'get around' to publishing data.

medium

The leak post

captured from the group's site

We have changed our contact method. We now exclusively use qTox Messenger for all communications. SimpleX and Session have been discontinued. Our Tox ID: A7580331D4D16453CCE86D7ADFBCF0CEED0D0D1AEA8F4DBEEBCA9E3B46308F260DE9B41BD838
You may have noticed the sudden, heavy silence. The corporate VPNs are dead. We have been the silent architects of your network for the past three weeks. While your "elite" investigators from Mandiant sat in your logs, we sat directly beside them burning through over a hundred of your corporate identities like disposable tools. we have had your entire network and internal protocols. HOW LONG WILL YOU KEEP YOUR THOUSANDS OF FIELD WORKERS LOCKED OUT? We have successfully exfiltrated the most sensitive engineering data held by any firm in your sectors We hold the complete Navisworks 3D models, P&ID diagrams, and maintenance logic for your major energy plants. This includes the granular Honeywell DCS controller logic. We know the flow, the pressure points, and the shutdown sequences of your clients' billion-dollar assets. We have completed our audit. Now, the choice belongs to the APTIM Executive Leadership and your partners at Hunt LNG. Currently, your compa…

Sources

Leak posthttp://fjg4zi4opkxkvdz7mvwp7h6goe4tcby3hhkrz43pht4j3vakhy75znyd.onion

Source

Indexed 7 days 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.