Grupo Ronda listed on lamashtu leak site

• Ransomware group: lamashtu
• Country: Mexico
• Sector: Professional Services
• Announcement date: April 14, 2026

Lamashtu claims data breach at Grupo Ronda

The threat actor known as lamashtu has listed the professional services firm Grupo Ronda on its dedicated leak site. According to the announcement made on April 14, 2026, the group claims to have successfully executed an attack against the organization, resulting in a significant data breach. This incident follows a common pattern observed in modern cybercrime, where threat actors utilize leak sites to pressure victims by threatening to publish sensitive information if demands are not met.

The group claims to have exfiltrated a substantial dataset belonging to the firm. This alleged dataset is reported to be approximately 58.7 GB in size and is said to consist of 6,308 individual files. The threat actor has indicated that the compromised information includes financial and legal documents that are part of the firm's operational history. Notably, the data is alleged to span a vast timeframe, ranging from 1993 to 2026, potentially exposing decades of historical records. While the group has announced the breach, public information regarding the specific capabilities or identity of the lamashtu group remains limited.

Alleged stolen data and contents

The information allegedly stolen by the threat actor is highly sensitive, covering various aspects of the firm's operations and its clients' private lives. The breach, if confirmed, involves a wide array of documentation that could be used for malicious purposes. The specific types of data mentioned in the claim include:

• National identity documents
• Banking details
• Property records
• Tax filings
• Digital certificates
• Legal proceeding documents
• Internal working papers

The presence of such diverse documentation suggests a deep penetration into the organization's digital infrastructure, targeting both administrative and client-facing repositories.

About Grupo Ronda

Grupo Ronda is a professional consulting firm based in Mexico. The organization provides a specialized suite of services, including auditing, insolvency mediation, accounting expertise, and legal services. The firm is managed by a professional team consisting of registered auditors and experts in business administration. Given the nature of their work, the firm handles a high volume of sensitive financial, legal, and personal information on behalf of their clients.

Impact and security implications

The nature of the alleged leaked data carries significant risks for the clients of Grupo Ronda. The exposure of national identity documents, banking details, and tax filings significantly increases the risk of identity theft and financial fraud for the affected individuals. For a professional services firm, the compromise of such sensitive financial and legal client data can lead to severe reputational damage and potential legal consequences for the organization.

Furthermore, the fact that the alleged data spans back to 1993 may indicate a long-term vulnerability in the firm's data security posture, suggesting that historical archives may not have been adequately protected against modern threats. There is also a technical risk regarding the leaked digital certificates and internal correspondence; these assets could potentially serve as an entry point for secondary attacks, such as supply chain attacks, against the firm or its partners.

In such scenarios, organizations often face administrative fines under local data protection regulations. To mitigate these risks, organizations in the professional services sector typically focus on robust encryption for data at rest and in transit, strict access controls, and comprehensive auditing of historical data archives. Implementing multi-factor authentication and regular security assessments are also standard defensive measures to prevent unauthorized access to sensitive client files.