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Mairie de Thiverval-Grignon

listed as Mairie Thiverval Grignon · Claimed by Medusalocker · listed 2 days ago

1d
Age
since listed · data leaked

Status timeline

  1. ListedJul 1, 2026
  2. Data leakeddate unknown

At a glance

Group
Medusalocker
Status
Data leaked
Country
France
Sector
Public Sector
Listed on leak site
Jul 1, 2026

About the victim

AI dossier — public-source company profile

Thiverval-Grignon is a municipality (commune) in France, governed by a mayor's office (mairie). The organization handles local administrative functions, citizen services, and municipal governance for the commune.

Industry
Local Government & Public Administration

Attack summary

Severity: high — Confirmed exfiltration of 162 emails from a public sector organization. Municipal email systems typically contain sensitive citizen data, administrative decisions, and potentially personal information of residents and staff. Public sector data breaches pose risks to citizen privacy and government operations.

Medusalocker claims to have extracted 162 emails from the municipality's domain. The group has published the data, indicating exfiltration of correspondence and likely administrative records.

high

Data the group says was taken

AI dossier — extracted from the leak post
  • Email accounts (162)
  • Municipal correspondence
  • Administrative records

What the group claims

Organization with 162 emails extracted. Domain: mairie-thiverval-grignon.fr

Sources

Source

Indexed 2 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.

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Disclosure context

About medusalocker

MedusaLocker is a ransomware operation first publicly documented around 2019, though the activity cluster reflected in this dataset shows observed campaigns beginning in November 2022, driven primarily by financial motivation with no known ideological or hacktivist agenda. The group is believed to operate out of or with ties to Eastern Europe, functioning as a Ransomware-as-a-Service model that allows affiliates to deploy the ransomware in exchange for a share of ransom proceeds, a structure documented in a joint advisory published by CISA, FBI, FinCEN, and HHS in June 2022. MedusaLocker actors typically gain initial access through phishing emails, exploitation of vulnerable Remote Desktop Protocol configurations, and compromised network devices, subsequently deploying the ransomware payload which encrypts victim files using AES-256 combined with RSA-2048 encryption while also exfiltrating sensitive data prior to encryption to enable double extortion pressure. Based on available telemetry, the group has claimed at least 67 known victims, with targeting concentrated heavily in the United States, United Kingdom, Brazil, France, and Israel, spanning sectors including business services, manufacturing, technology, and education, consistent with the opportunistic rather than highly selective targeting pattern characteristic of RaaS affiliate programs. As of the time of writing, MedusaLocker remains an active threat with no confirmed law enforcement disruption, takedown operation, or confirmed rebrand publicly attributed to the group by major intelligence or law enforcement agencies. The group has been linked to 77 public disclosures across our corpus. First observed on a leak site on November 15, 2022; most recent post July 1, 2026. The operation is currently active.

Timeline of this disclosure

  • July 1, 2026Mairie Thiverval Grignon listed by medusalockeron the group's public leak site

Other recent disclosures by medusalocker

medusalocker has been linked to 77 public victims on Darkfield. A sample of the most recent:

See the full medusalocker dossier →

Sector and geography

This disclosure adds to ransomware activity in the Public Sector sector, which has 466 disclosures indexed across all operators we track. Geographically, Mairie Thiverval Grignon is reported in France, a country with 240 ransomware disclosures in our corpus.

If your organisation is affected

A listing by medusalocker means Mairie Thiverval Grignon appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

  • Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
  • Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
  • Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
  • Report the incident to your national CERT, CERT-FR (France), as required for your jurisdiction.
  • Monitor for the data appearing on medusalocker's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

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.