CCJM Listed by sinobi Ransomware Group: Ransomware Claim — What’s Alleged & What To Do

On December 3, 2025, the ransomware group sinobi listed the engineering firm CCJM on its leak site. The listing states that internal files were exfiltrated in a ransomware attack. No further details on the scale of the incident or the number of people affected have been made public. The practical stakes center on the types of records an engineering firm maintains for public and private infrastructure projects. Any exposure of project documentation, client correspondence, or operational data could affect individuals and organizations tied to those projects, even if the full extent of the incident is still unclear.

What happened

The incident was reported on December 3, 2025, when sinobi added CCJM to its leak site. The group claims internal files were taken during a ransomware operation. No information has been released on the date of the intrusion itself, the volume of data involved, or whether any files were subsequently published.

Public records do not indicate whether CCJM has stated the listing or provided its own account of events. The number of people affected is listed as unknown.

The group behind it: sinobi

Sinobi is a ransomware operation that maintains a leak site to post names of organizations it claims to have targeted. Such groups typically gain initial access through common vectors such as compromised remote-access tools or stolen credentials, then move laterally to locate and copy data before deploying encryption.

The listing of CCJM constitutes the group’s claim of responsibility. No independent confirmation of the claim has been reported in available information.

CCJM and its sector

CCJM is a multi-disciplined engineering firm that has operated since 1979. Its services cover buildings and facilities, civil and site work, construction management, energy solutions, smart technology, surveying, transportation, and water and wastewater management. The firm works with both public-sector and private-sector clients.

Organizations in this sector routinely handle technical drawings, contract documents, site assessments, and correspondence with government agencies and utilities. A breach at such a firm can therefore touch records that extend beyond the company itself to the projects it supports.

What data was at risk

The only detail provided is that internal files were allegedly exfiltrated. The specific categories of information contained in those files have not been disclosed.

Engineering firms of this type commonly store project specifications, client contact details, financial records related to contracts, and regulatory submissions. Without a confirmed inventory, it is not possible to state which of these categories, if any, were involved.

The real-world impact

Individuals and organizations connected to CCJM’s projects may face secondary risks if their details appear in the exfiltrated material. These could include follow-on attempts to use exposed credentials or to leverage project information for further targeting.

For the firm, the incident adds to the operational and reputational costs already associated with ransomware events, including any recovery work and potential regulatory scrutiny common in the engineering and infrastructure sector.

What to do if you're exposed

Anyone who has worked with CCJM or its projects should treat the situation as a standard data-exposure event until more details emerge.

• Change passwords for any accounts linked to the firm and enable multi-factor authentication where available.
• Monitor bank and credit accounts for unusual activity and consider placing a fraud alert with major credit bureaus.
• Watch for official notices from CCJM or regulators that may provide further guidance on the scope of the incident.
• Run a free exposure scan of your email address against known breach data to check for prior appearances of your information.

AICompiled with AI assistance from public sources and published under our editorial standards.