RansomHub ransomware group lists www.assisi.nl on its leak site

• Ransomware group: RansomHub
• Country: Netherlands
• Sector: Healthcare
• Announcement date: March 29, 2025

RansomHub claims data breach against Assisi

The ransomware group known as RansomHub has officially listed the Dutch healthcare organization Assisi on its dedicated leak site. According to the announcement made by the threat actors, the group has published various documents and files that they claim belong to the organization. This development follows a period of inactivity for the group, as the leak appears to be part of their final operations before they reportedly ceased operations in early 2025.

The timeline provided by the threat group suggests that the alleged breach occurred on February 17, 2025. The public disclosure of this data was subsequently announced on the group's leak site on March 29, 2025. RansomHub, a Ransomware-as-a-Service (RaaS) model that emerged in early 2024, gained notoriety after reportedly absorbing various affiliates following the ALPHV incident. While the group was reported to have ceased operations in early 2025, this recent listing indicates that the breach may be among the group's final activities.

Details of the alleged data leak

The information released by RansomHub involves a variety of sensitive documentation. Based on the screenshots provided by the threat actors, the leaked content includes several types of highly sensitive information that could impact the organization's operations and the privacy of individuals associated with it. The specific types of data identified in the claim include:

• Bank account details
• Insurance policies
• Employment contracts
• Commercial documents

The disclosure of such diverse documentation, ranging from financial details to legal employment agreements, highlights the potential scope of the incident. While the group has published these files, they have not provided specific information regarding the total size of the data stolen or the specific number of files involved in the breach.

About Assisi

Assisi is a healthcare organization based in the Netherlands. The organization provides essential care and support services, with a specific focus on serving the elderly and individuals with disabilities. Their mission centers on delivering personalized care solutions designed to improve the overall quality of life for their clients and those under their care.

Impact and security implications

The alleged leak of this data poses significant risks to the organization's employees and business partners. The exposure of bank account details, insurance policies, and employment contracts creates a high risk for identity theft and the execution of targeted phishing attacks against the individuals involved. Furthermore, the disclosure of commercial and financial documents increases the secondary risks for third parties who interact with the organization.

Because Assisi is based in the Netherlands, this breach may be subject to investigation by data protection authorities under the General Data Protection Regulation (GDPR). Such incidents often require organizations to undergo rigorous scrutiny regarding their data handling and protection protocols. In the healthcare sector, where sensitive personal information is a core component of operations, the impact of a breach can be particularly profound.

To mitigate the risks associated with such threats, organizations typically focus on robust defensive measures. This includes implementing strict access controls, maintaining comprehensive logging and monitoring to detect unauthorized access, and conducting regular security awareness training to help staff recognize phishing attempts. Additionally, maintaining offline, encrypted backups and ensuring that all software is patched against known vulnerabilities are standard industry practices to defend against ransomware and data exfiltration tactics.