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 29, 2025J. E. Stacey & Co. Ltd (jestacey.com) listed by Jon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Construction sector, which has 415 disclosures indexed across all operators we track. Geographically, J. E. Stacey & Co. Ltd (jestacey.com) is reported in United Kingdom, a country with 902 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

J. E. Stacey & Co. Ltd (jestacey.com)

Claimed by J · listed 8 months ago

Age

since listed · data leaked

Status timeline

Listed
Sep 29, 2025
Data leaked

At a glance

Group: J
Status: Data leaked
Country: United Kingdom
Sector: Construction
Listed on leak site: Sep 29, 2025

About the victim

AI dossier — public-source company profile

J. E. Stacey & Co. Ltd is a privately owned, multi award-winning independent building and civil engineering contractor based in Holsworthy, Devon, operating throughout Devon, Cornwall and the South West of England. Established in 1932, the company employs approximately 40 permanent staff and delivers a full range of building services including construction, restoration & heritage, bespoke joinery, residential & small works, and plumbing & heating. It serves residential, commercial and industrial clients and is capable of delivering full design-and-build projects.

Industry: Building & Civil Engineering Contracting
Address: Inceworth Building Works, Holsworthy, Devon, EX22 6BD, United Kingdom
Employees: 40
Founded: 1932

Attack summary

Severity: medium — Data has been published (not merely listed), indicating confirmed exfiltration; however, the leak post provides no detail on data volume, type or sensitivity, and the company is a small (~40 employee) regional contractor with no indication of regulated or large-scale personal data at stake.

Group J claims to have compromised J. E. Stacey & Co. Ltd and has published data (disclosed status: data_published), though the leak post does not specify whether encryption occurred or detail the volume of exfiltrated data.

medium

Data the group says was taken

AI dossier — extracted from the leak post

Company business data
Potentially employee records
Potentially client/project records

Original description

AI-summarised, not from the leak post

J. E. Stacey & Co. Ltd is a UK-based civil engineering firm specializing in the construction industry. Established in 1974, the company provides services such as road works, bridge construction, earthmoving, landfill works, environmental improvements, and more. They have a qualified and experienced workforce known for delivering quality work while maintaining high safety and environmental standards.

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.