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

October 27, 2025ATIRG listed by Medusaon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Not Found sector, which has 4,859 disclosures indexed across all operators we track. Geographically, ATIRG is reported in French Guiana.

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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ATIRG

Claimed by Medusa · listed 7 months ago

Age

since listed · data leaked

Status timeline

Listed
Oct 27, 2025
Data leaked

At a glance

Group: Medusa
Status: Data leaked
Country: French Guiana
Sector: Not Found
Listed on leak site: Oct 27, 2025

About the victim

AI dossier — public-source company profile

ATIRG is a company based in French Guiana. No public site content or leak post details were available to determine the nature of its operations, scale, or industry.

Attack summary

Severity: medium — Data is marked as published by the group, indicating confirmed exfiltration rather than a mere listing, but no details about data type, scale, or sensitivity are available to elevate to high or critical.

Medusa ransomware group has listed ATIRG with a disclosed status of 'data_published', suggesting data exfiltration has occurred; however, no specific claims about encryption, data types, or volume were extractable from the truncated leak post.

medium

What the group claims

ATIRG (Association pour le Traitement de l’Insuffisance Rénale en Guyane) is a non-profit medical organization located in French Guiana, dedicated to providing dialysis treatment and kidney care for patients suffering from chronic renal failure. Established in 1981, ATIRG operates several autodialysis centers in Cayenne, Kourou, and Saint-Laurent-du-Maroni, offering patients the opportunity to manage their own dialysis under professional supervision. The organization focuses on improving patients’ quality of life through medical care, training, and nutritional support. ATIRG works closely with local hospitals and healthcare professionals to ensure safe, effective, and continuous kidney treatment across the region. company is headquartered in 1361 Route de Baduel, 97300 Cayenne, French Guiana.

The leak post

captured from the group's site

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Sources

Leak posthttp://xfv4jzckytb4g3ckwemcny3ihv4i5p4lqzdpi624cxisu35my5fwi5qd.onion/detail?id=94b263b82b7111168b1e46266efef67f

Source

Indexed 7 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.