Disclosure context

About Medusa

Medusa, also known as MedusaLocker, is a financially motivated ransomware group that emerged in November 2022 and has since compromised 568 known victims across multiple countries. The group's origin and specific affiliations remain unclear from publicly available intelligence, though their operational patterns suggest they function as an independent ransomware operation rather than a documented Ransomware-as-a-Service model. Medusa primarily targets organizations in the United States, United Kingdom, Canada, Italy, and Australia, with a focus on business services, healthcare, manufacturing, and technology sectors, employing typical ransomware tactics including data encryption and likely exfiltration for double extortion purposes, though specific technical methodologies and initial access vectors have not been extensively documented in public threat intelligence reports. While the group has maintained a relatively high victim count since its emergence, detailed information about specific notable campaigns, high-profile victims, or major ransom demands has not been widely reported by major cybersecurity firms or law enforcement agencies. As of current intelligence assessments, Medusa appears to remain active in the threat landscape, continuing to target organizations across their established geographic and sectoral preferences. The group has been linked to 568 public disclosures across our corpus. First observed on a leak site on November 15, 2022; most recent post February 14, 2026. The operation is currently active.

Also tracked as: MedusaLocker.

Timeline of this disclosure

December 28, 2025JBS listed by Medusaon the group's public leak site

Data size: 168.6 GB
Records: 500 Employees

Sector and geography

This disclosure adds to ransomware activity in the Healthcare sector, which has 1,779 disclosures indexed across all operators we track. Geographically, JBS is reported in United States, a country with 7,392 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

JBS

Claimed by Medusa · listed 5 months ago

168.6 GB

Data size

500 Employees records

Age

since listed · data leaked

Status timeline

Listed
Dec 28, 2025
Data leaked

At a glance

Group: Medusa
Status: Data leaked
Country: United States
Sector: Healthcare
Listed on leak site: Dec 28, 2025
Data size: 168.6 GB
Records: 500 Employees

About the victim

AI dossier — public-source company profile

JBS S.A. is one of the world's largest meat processing companies, headquartered in São Paulo, Brazil, with major US operations based in Greeley, Colorado. The company processes beef, pork, and poultry across dozens of facilities in the United States and globally. JBS USA is a dominant supplier to retail, foodservice, and export markets worldwide.

Industry: Meat & Protein Processing
Employees: 150000+
Founded: 1953

Attack summary

Severity: high — 168.6 GB of data is confirmed published by a known ransomware group against a major global food processing company. JBS has been targeted before (REvil, 2021), and the scale of exfiltration suggests significant business and potentially employee/operational data exposure. The sector label of 'Healthcare' appears misclassified; JBS is food/meat processing. No direct evidence of regulated medical or government data, so 'critical' is not warranted, but the volume and prior attack history elevate thi

The Medusa ransomware group claims to have exfiltrated approximately 168.6 GB of data from JBS and has published the data. The leak post content is obscured by a CAPTCHA wall, preventing direct verification of specific data types claimed.

high

Data the group says was taken

AI dossier — extracted from the leak post

Corporate files (inferred from 168.6 GB exfiltration claim)
Potentially employee records
Potentially financial documents
Potentially operational data

What the group claims

JBS is a regional, public, nonprofit corporation established under Act 310 of the 1967 Alabama Legislature. The region served by the Authority is designated in the State Mental Health Plan as Region M-5, and comprises Jefferson, Blount and St. Clair counties, with a total of more than 800,000 residents. There are three mental health centers which serve the region. It is the responsibility of the Authority to plan, coordinate and develop the system of mental health services for the entire region. The Authority provides consultation regarding program development and funding; coordination of regional programs; delivery of region-wide services; and a consolidated budgeting process to simplify the funding of programs at the local and state level. company is headquartered in 940 Montclair Rd., Birmingham, AL 35213, USA. 201-500 Employees, The total amount of data leakage is 168.6 GB.

The leak post

captured from the group's site

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Sources

Leak posthttp://xfv4jzckytb4g3ckwemcny3ihv4i5p4lqzdpi624cxisu35my5fwi5qd.onion/detail?id=41d10752afc874fc21305afdf3e01b62

Source

Indexed 5 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.