Disclosure context

About J

The J ransomware group is a newly emerged threat actor first observed in May 2025, operating with apparent financial motivations based on their targeting patterns across multiple countries and sectors. With limited public documentation available from established security research organizations, the group has demonstrated rapid operational capability by compromising 41 known victims within their initial months of activity. Their targeting strategy appears opportunistic, focusing primarily on organizations in the United States, United Kingdom, France, Argentina, and Germany, with a particular emphasis on technology companies, manufacturing firms, construction businesses, and business services providers. The diversity of their geographic and sectoral targeting suggests either a broad-spectrum approach to victim selection or potential use of automated tools for initial compromise identification. Given the recent emergence of this group and limited reporting from major cybersecurity firms and law enforcement agencies, specific details regarding their technical methodologies, ransom demands, data exfiltration practices, or organizational structure remain undocumented in publicly available threat intelligence. The group remains active as of current reporting periods, though their relative obscurity in established threat intelligence databases suggests they may be operating at a smaller scale compared to more prominent ransomware-as-a-service operations. The group has been linked to 41 public disclosures across our corpus. First observed on a leak site on May 2, 2025; most recent post November 9, 2025. The operation is currently inactive.

Timeline of this disclosure

July 30, 2025gimaex.com listed by Jon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Manufacturing sector, which has 2,458 disclosures indexed across all operators we track. Geographically, gimaex.com is reported in France, a country with 472 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

gimaex.com

Claimed by J · listed 10 months ago

Age

since listed · data leaked

Status timeline

Listed
Jul 30, 2025
Data leaked

At a glance

Group: J
Status: Data leaked
Country: France
Sector: Manufacturing
Listed on leak site: Jul 30, 2025

About the victim

AI dossier — public-source company profile

Gimaex is a French manufacturer of custom fire and rescue vehicles, operating two production facilities in Mitry-Mory and Roanne. The company produces approximately 250 vehicles annually and serves over 100 countries with specializations in urban, forestry, industrial, airport, and special-application firefighting vehicles.

Industry: Emergency Vehicle Manufacturing
Address: 8 rue Henri Becquerel, Z.I. de Mitry-Compans, BP 215, 77292 Mitry-Mory Cedex, France (headquarters); also production facility in Roanne (42)
Employees: 120

Attack summary

Severity: medium — Data has been published (disclosed_status = 'data_published'), confirming exfiltration occurred. However, no specific data categories, proof file counts, or operational impact are detailed in the available post. The company handles sensitive operational and customer data (international military/civil contracts, vehicle designs), but no regulated PII at scale is explicitly confirmed.

Group J claims to have conducted an attack on Gimaex and has published data. The leak post does not specify whether encryption, exfiltration, or both occurred, nor does it detail what data categories were compromised.

medium

Original description

AI-summarised, not from the leak post

Gimaex is a leading French company specializing in the design and manufacturing of fire and rescue vehicles. With a history spanning over four decades, they are known for innovations and high-quality custom emergency vehicles. They build a range of equipment including fire trucks, firefighting equipment, ambulance vehicles, and special vehicles for civil and military applications.

Sources

Source

Indexed 10 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.