gunra ransomware group lists miraense.com on its leak site

• Ransomware group: gunra
• Country: Brazil
• Announcement date: October 1, 2025

The gunra ransomware group claims a massive data breach at Miraense

The threat actor group known as gunra has listed miraense.com on their leak site, claiming to possess a significant volume of stolen information. According to the announcement, the group asserts that they have acquired 8TB of data belonging to the organization. This type of activity is a hallmark of modern ransomware operations, where attackers often employ double extortion tactics. In such scenarios, threat actors not only encrypt an organization's systems to disrupt operations but also steal sensitive data to use as leverage, threatening to leak it on public forums if a ransom is not paid.

The announcement was made on October 1, 2025. While the group has published a directory structure that allegedly belongs to the organization, public information regarding the specific identity, methods, or background of the gunra group remains limited. This lack of public intelligence makes it difficult for security researchers to attribute the attack or understand the group's specific technical capabilities.

Details of the alleged data theft

The leak announcement includes a directory structure that provides a glimpse into the types of files the group claims to have exfiltrated. Based on the information provided in the leak post, the compromised data appears to include several critical categories of information. The presence of these directories suggests a wide-ranging intrusion into the organization's digital environment. The specific directories identified in the announcement include:

• Database files
• Personal data
• Sharepoint documents

The screenshots provided by the threat actor display these specific labels, such as 'database', 'personal', and 'sharepoint'. However, it is important to note that there is no detailed information available regarding the full scope and nature of the leaked data. The exact contents of these directories and the full extent of the breach have not been disclosed in detail by the attackers.

About Miraense

Miraense is a Brazil-based energy and engineering company. The organization specializes in services related to energy transmission, distribution, and infrastructure projects. Given its role in critical infrastructure and energy services, the company operates within a sector that is often a target for sophisticated cyber threats due to the sensitive nature of the services provided.

Implications and organizational risks

The presence of directories labeled 'personal' and 'database' suggests that sensitive information belonging to employees or customers may be at risk of exposure. For an organization operating in Brazil, such an incident may lead to legal obligations and administrative sanctions under the LGPD (General Data Protection Law). The potential exposure of such data can have long-term consequences for both the organization and the individuals affected.

The exposed data could potentially be utilized for identity theft or targeted phishing attacks against the organization. Furthermore, the inclusion of a 'sharepoint' directory indicates that internal corporate processes and confidential documents might have been compromised. When internal collaboration platforms like SharePoint are accessed, it can lead to the exposure of proprietary business logic and strategic documents.

In general, when organizations face such threats, they may need to fulfill data breach notification requirements and inform the affected parties. Defensive measures typically involve strengthening access controls, implementing multi-factor authentication, and maintaining rigorous monitoring of data exfiltration patterns. As organizations in the energy and engineering sectors continue to digitize, protecting the integrity of databases and document repositories remains a critical component of cybersecurity resilience.