MedusaLocker ransomware group lists SIT Group / Robusta on its leak site

• Ransomware group: MedusaLocker
• Country: Italy
• Sector: Professional Services
• Announcement date: May 5, 2026

The MedusaLocker ransomware group has claimed to have published data belonging to SIT Group and Robusta on its dedicated leak site. This announcement, made on May 5, 2026, suggests a potential data breach involving these entities, though the claims remain unverified.

The details of the claim

According to the announcement posted on the MedusaLocker leak site, the group listed SIT Group and Robusta on May 5, 2026. The group claims to have successfully published data associated with these specific entities. On the leak site, the names of the institutions are displayed alongside a directory structure, which is a common method used by ransomware groups to demonstrate the scale and nature of the data they have allegedly exfiltrated.

Ransomware groups often employ a tactic known as double extortion. In this scenario, attackers do not only encrypt an organization's files to disrupt operations but also steal sensitive information. They then threaten to release this data on public leak sites if the ransom is not paid. This method increases the pressure on the victim by threatening their reputation and legal standing through the exposure of private information.

Information regarding the leaked data

While the leak site provides a visual representation of the stolen information, specific details remain limited. The screenshot provided by the group on their platform shows a folder structure named 'sorted'. However, there is no detailed information regarding the specific nature or content of the leaked data available at this time. The listing does not specify the volume of data or the exact types of files that have been compromised.

Affected data types

The current listing names no specific data types.

Organization profile

SIT Group is an Italian technology company that specializes in the development of smart metering solutions and control systems. Their technological focus includes measurement for gas and water, as well as systems for heating and cooking appliances. The company is primarily centered on digitalization products and energy efficiency solutions.

Implications and defensive considerations

This claim may pose a significant risk to the operational continuity and data privacy of the institutions involved. Because the entities are based in Italy and Bulgaria, a confirmed breach could trigger legal processes under the General Data Protection Regulation (GDPR). Such regulations impose strict requirements on how personal data is handled and how breaches must be reported to authorities and affected individuals.

The publication of data can lead to various secondary threats, such as identity theft or targeted phishing attacks directed at employees or customers. When sensitive information is leaked, attackers often use it to craft highly convincing social engineering campaigns to gain further access to corporate networks or to defraud individuals.

As information regarding the MedusaLocker group is limited, it is difficult to assess their specific tactics, techniques, and procedures. For organizations facing such claims, it is advisable to investigate the leak claims thoroughly to confirm the validity of the breach. If a breach is confirmed, organizations should fulfill necessary notifications to regulatory bodies and affected parties. Furthermore, reviewing and strengthening security measures is a critical step in mitigating the impact of current and future cyber threats.

General defensive measures

To defend against ransomware and data exfiltration, organizations typically focus on several key areas:

• Implementing robust backup solutions that are isolated from the main network.
• Enforcing multi-factor authentication across all external-facing services.
• Maintaining rigorous patch management to close vulnerabilities.
• Conducting regular security awareness training for all employees.