The Structures Group listed on sinobi leak site

• Ransomware group: sinobi
• Country: United States
• Sector: Professional Services
• Announcement date: January 8, 2026

The Structures Group, a United States-based professional services firm, has been listed on a leak site associated with the threat actor known as sinobi. According to the announcement made on January 8, 2026, the threat actor claims to have compromised a significant amount of data belonging to the organization.

Details of the alleged attack

The threat actor identified as sinobi claims to have conducted an attack against The Structures Group on January 5, 2026. In the listing, the actor asserts that they have successfully exfiltrated a data set totaling 140 GB in size. Following the alleged theft, the group has issued a ransom demand of 5,000,000 USD to the organization.

Publicly available information regarding the sinobi group remains limited, making it difficult to establish a comprehensive profile of their typical tactics, techniques, or procedures. This incident follows a common pattern seen in modern ransomware operations, often referred to as double extortion. In these scenarios, attackers do not merely encrypt an organization's systems to disrupt operations; they also steal sensitive information to use as leverage, threatening to leak the data on public forums if the ransom is not paid.

Alleged compromised data

The information allegedly stolen during this incident is said to include various types of sensitive documentation. The leak site listing claims that the following data types have been compromised:

• Contracts
• Customer data
• Financial data

The exposure of such information can lead to various secondary risks. For instance, when sensitive business documents are leaked, they can be utilized by malicious actors to conduct targeted phishing campaigns or identity theft. Such attacks often leverage the specific context of the stolen data to appear more legitimate to the intended victims.

About The Structures Group

The Structures Group is a consulting engineering firm that specializes in several technical areas, including structural engineering, special inspections, and forensic analysis. The firm provides a range of professional services, such as independent review plans and risk analysis, for various types of projects, including commercial, residential, and institutional developments.

Impact and industry implications

This alleged data leak may pose significant privacy risks to the organization's clients and business partners. The exposure of financial records and contracts could damage the firm's commercial reputation and potentially lead to legal consequences. Because the organization is based in the United States, the incident may subject the firm to state-level data breach notification laws and other relevant regulatory requirements.

Furthermore, the incident may place pressure on the firm's operational continuity and could lead to secondary risks regarding supply chain security. In the professional services sector, where trust and confidentiality are paramount, a breach of this nature can have ripple effects throughout a client's own operations.

To defend against such threats, organizations in the professional services sector typically implement various defensive measures. These include robust access controls, multi-factor authentication, and continuous monitoring of network traffic to detect unauthorized data exfiltration. Regular backups, stored offline or in immutable environments, remain a critical component of a resilient cybersecurity posture to ensure operational continuity in the event of a successful encryption attack.