Disclosure context

About MEDUSA LOCKER (aka BAVACAI

MedusaLocker (also identified under the alias BAVACAI) is a ransomware group first observed in May 2026, operating with a primary financial motivation consistent with contemporary cybercriminal ransomware operations. Due to the extremely limited public documentation available at this time — with only a single known victim on record and a very recent emergence date — comprehensive attribution, origin, and affiliation details cannot be responsibly stated without risking speculation beyond what is publicly confirmed by authoritative sources such as CISA, the FBI, or Mandiant. It should be noted that a separate, well-documented ransomware family also named MedusaLocker has been publicly tracked since 2019 and operates as a Ransomware-as-a-Service model; whether this BAVACAI-aliased entity represents a rebrand, offshoot, or entirely distinct group sharing the name is not confirmed by available public intelligence. Given the single known victim and the May 2026 first-observed date, this group should be considered an emerging or early-stage threat with minimal public threat intelligence footprint, and analysts are advised to treat any further characterization as preliminary pending additional reporting from law enforcement or the security research community. Monitoring for additional victim disclosures, leak site activity, and technical indicators will be necessary to develop a more complete operational profile. The group has been linked to 4 public disclosures across our corpus. First observed on a leak site on May 15, 2026; most recent post May 20, 2026. The operation is currently active.

Timeline of this disclosure

May 16, 2026Académie de Montpellier / CSJM listed by MEDUSA LOCKER (aka BAVACAIon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Education sector, which has 694 disclosures indexed across all operators we track. Geographically, Académie de Montpellier / CSJM 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

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Académie de Montpellier / CSJM

Claimed by MEDUSA LOCKER (aka BAVACAI · listed 5 days ago

Age

since listed · data leaked

Status timeline

Listed
May 16, 2026
Data leaked

At a glance

Group: MEDUSA LOCKER (aka BAVACAI
Status: Data leaked
Country: France
Sector: Education
Listed on leak site: May 16, 2026

About the victim

AI dossier — public-source company profile

Académie de Montpellier is a French regional education authority (rectorat) overseen by the French Ministry of National Education, responsible for administering primary, secondary, and higher education across the Hérault, Gard, Lozère, and Pyrénées-Orientales departments. The CSJM (Centre de Services du Jury des Mentions) likely refers to an administrative unit within or affiliated with the academy. As a public institution, it manages student records, staff data, and educational operations for a large geographic area in southern France.

Industry: Public Education Administration
Address: 31 rue de l'Université, 34064 Montpellier Cedex 2, France
Employees: 1001-5000

Attack summary

Severity: high — The victim is a public education authority handling PII at scale including student and staff records; data has been published (disclosed status: data_published) with demo files already accessible, indicating confirmed exfiltration of sensitive personal data from a government-affiliated institution.

MEDUSA LOCKER (aka BAVACAI) claims to have exfiltrated data from Académie de Montpellier / CSJM and has published demo access showing up to 10 files per folder as proof, with full data to be released following publication. The nature of the exfiltrated data has not been fully detailed in the truncated post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Student records
Staff personal data
Administrative documents
Internal correspondence

The group's post references roughly 10 proof files.

What the group claims

French academic institution - Académie de Montpellier / CSJM

The leak post

captured from the group's site

## Académie de Montpellier / CSJM
⚠ Demo access — showing up to 10 files per folder. Full data will be available after publication.

Screenshot of the leak post

Leak screenshot for Académie de Montpellier / CSJM

Sources

Leak posthttp://t33zoj4qwv455fog7qnb2azi5xcdxkixughmmduzbw2rtdgryqfbh6id.onion/company/baiapai/

Source

Indexed 5 days 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.