Skip to main content
Darkfield

Ransomware victim disclosure

← All victims

Nihon Kotsu Co., Ltd.

Claimed by AiLock · listed 2 months ago

6 TB
Data size
46d
Age
since listed · data leaked

Status timeline

  1. ListedJul 15, 2026
  2. Data leakeddate unknown

At a glance

Group
AiLock
Status
Data leaked
Country
Japan
Sector
Transportation/Logistics
Listed on leak site
Jul 15, 2026
Data size
6 TB

About the victim

AI dossier — public-source company profile

Nihon Kotsu Co., Ltd. is Japan's largest taxi and limousine operator by group sales, founded in 1928. The company operates approximately 10,000 taxis and hire vehicles across Tokyo, the greater Kanto region, and Kansai, providing passenger transportation and driver dispatch services.

Industry
Taxi & Limousine Services
Address
Tokyo, Japan (headquarters); operations across Tokyo, Kanto, and Kansai regions
Founded
1928

Attack summary

Severity: high — Confirmed operational disruption to critical infrastructure (transportation operator with 10,000+ vehicles); company's own website notes 'system outage due to unauthorized access'. Large-scale operational impact on national transportation network justifies high severity despite lack of confirmed data exfiltration details.

AiLock claims to have conducted an attack on Nihon Kotsu's systems resulting in operational disruption. No specific details of data exfiltration, encryption scope, or data categories are disclosed in the leak post.

high

What the group claims

Nihon Kotsu Co., Ltd. is the largest taxi and limousine operator in Japan. For the fiscal year ending May 2025, the company reported an annual consolidated revenue of ¥103.445 billion, with group and partner company sales reaching ¥155.457 billion.

The leak post

captured from the group's site
Good morning. Thou hast had a good night's sleep, I hope.
FUJIFILM Speciality Ink Systems 6Tb uncompressed data
proservicecall.com prvn.com 199Gb uncompressed data
nihon-kotsu.co.jp 2.9Tb contain about 8,000 driver's licenses 
Integral Analytics specializes in data intelligence solutions for the energy sector, focusing on improving planning and forecasting for utilities, producers, manufacturers, and regulators. Their flagship products include LoadSEER, DSMore, and IDROP, which assist in energy efficiency, demand response, and distributed energy resource management.
AJ Networks Co. Ltd is a company that operates in the Other Rental Stores (Furniture, A/V, Construction & Industrial Equipment) industry. It employs 500to999 people and has 500Mto1G of revenue. The company is headquartered in Seoul, South Korea.
Revival Animal Health was founded in 1989 by Dr. Roy Nielsen, Jr., affectionately known as "Doc Roy." Quickly the company expanded from pet vaccines to an extensive line of pet healthcare products.
HomeSite Services Inc., a residential, commercial and retail services company, was founded in 2005 with three goals in mind: to perform superior work, offer quality products, and prov…

Screenshot of the leak post

Leak screenshot for Nihon Kotsu Co., Ltd.

Sources

Source

Indexed 2 months 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.

Is this your supplier? Your competitor? You?

Pro plans monitor your domain, corporate emails, and crypto wallets across every new ransomware leak-site post, breach dump and Telegram callout — alerts within 5 minutes.

Disclosure context

About AiLock

AiLock is an emerging ransomware group first observed in March 2026 with a primarily financial motivation, having targeted at least 24 known victims across multiple sectors. The group's origin and affiliations remain largely undocumented by major threat intelligence organizations, though their targeting patterns suggest a broad operational scope spanning the United States, Canada, Great Britain, China, and Germany. Based on publicly available information from security researchers, AiLock appears to focus on technology companies, consumer services, manufacturing, and public sector entities, though specific attack methodologies, initial access vectors, and encryption techniques have not been extensively documented by CISA, FBI, or major security firms. The group's relatively recent emergence and limited public documentation suggest they may be a smaller operation or newly formed entity, with no notable major campaigns or high-profile ransoms publicly reported by established threat intelligence sources. Given the March 2026 first observation date and lack of subsequent major public reporting, AiLock's current operational status and capabilities remain largely undetermined by mainstream cybersecurity organizations. The group has been linked to 51 public disclosures across our corpus. First observed on a leak site on March 3, 2026; most recent post August 26, 2026. The operation is currently active.

Timeline of this disclosure

  • July 15, 2026Nihon Kotsu Co., Ltd. listed by AiLockon the group's public leak site
Data size
6 TB

Other recent disclosures by AiLock

AiLock has been linked to 51 public victims on Darkfield. A sample of the most recent:

See the full AiLock dossier →

Sector and geography

This disclosure adds to ransomware activity in the Transportation/Logistics sector, which has 1,081 disclosures indexed across all operators we track. Geographically, Nihon Kotsu Co., Ltd. is reported in Japan, a country with 89 ransomware disclosures in our corpus.

If your organisation is affected

A listing by AiLock means Nihon Kotsu Co., Ltd. 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 AiLock'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.