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

September 23, 2025FAI Aviation Group (fai.ag) - The biggest leak ever listed by Jon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Transportation/Logistics sector, which has 847 disclosures indexed across all operators we track. Geographically, FAI Aviation Group (fai.ag) - The biggest leak ever is reported in Germany, a country with 695 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

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FAI Aviation Group (fai.ag) - The biggest leak ever

Claimed by J · listed 8 months ago

Age

since listed · data leaked

Status timeline

Listed
Sep 23, 2025
Data leaked

At a glance

Group: J
Status: Data leaked
Country: Germany
Sector: Transportation/Logistics
Listed on leak site: Sep 23, 2025

About the victim

AI dossier — public-source company profile

FAI Aviation Group (FAI AG) is a Germany-based global provider of mission-critical aviation services headquartered in Nuremberg. The company offers private jet charter, aircraft management, air ambulance, and special mission services, operating one of the largest private aircraft fleets in Europe. It serves clients across medical, government, corporate, and humanitarian sectors worldwide.

Industry: Aviation Services & Aircraft Charter
Address: Flughafenstraße 100, 90411 Nuremberg, Germany
Employees: 501-1000
Founded: 1989

Attack summary

Severity: critical — Data has been confirmed as published by the threat actor. FAI Aviation Group handles sensitive government, military special mission, and air ambulance clients, meaning exfiltrated data is highly likely to include regulated PII, medical records (air ambulance), and potentially government/defence-related operational information at significant scale.

The ransomware group 'J' claims to have exfiltrated data from FAI Aviation Group and has published the data (disclosed status: data_published), describing it as 'the biggest leak ever'; no ransom amount or specific data volume was stated in the post.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Corporate documents
Client records
Flight/mission operational data
Employee records
Financial records
Government/special mission client data

Original description

AI-summarised, not from the leak post

FAI Aviation Group is a global aviation service provider based in Germany. The company offers services including aircraft charter, aircraft management, air ambulance services, and special mission services. It owns a fleet of jets and helicopters, making it one of the largest aircraft operators in Europe. The term "The biggest leak ever" does not directly relate to the company's core operations.

Sources

Source

Indexed 8 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.