MONTALBAARCHITECTS.COM Listed by clop Ransomware Group: Ransomware Claim — What’s Alleged & What To Do

On January 25, 2026, the ransomware group Clop listed MONTALBAARCHITECTS.COM on its leak site. The listing states that internal files were exfiltrated from the architecture firm during a ransomware attack. The number of people affected has not been disclosed, and no further details on the scale or method of the operation have been made public. This incident forms part of a broader pattern in which ransomware operators target professional services firms that hold project documentation and client records. Such listings draw attention because they signal that data has left the organisation, even when the contents remain unverified by independent sources.

What happened

The only confirmed information is the leak-site listing itself. Clop claims to have obtained internal files from MONTALBAARCHITECTS.COM. No date of the intrusion, volume of data, or confirmation of encryption has been released by the organisation or by investigators. The number of individuals whose information may be involved is reported as unknown.

Who is clop?

Clop is a ransomware group that has conducted operations since at least 2019. Public reporting has documented its use of double-extortion tactics, in which data is encrypted on victim systems and copies are removed for later publication if ransom demands are not met. The group has appeared on leak sites with entries from multiple sectors, though each listing represents an unverified claim by the operators until corroborated by the affected organisation or law-enforcement findings.

About MONTALBAARCHITECTS.COM

Montalba Architects, Inc. is a firm with offices in Santa Monica, California, and Lausanne, Switzerland. It was founded by David Montalba and undertakes both residential and commercial projects. Architecture practices routinely maintain records that include design specifications, client correspondence, site plans, and regulatory submissions. A breach at such an organisation can expose material that is not inherently personal yet remains sensitive to the clients and projects involved.

What data was at risk

The listing refers only to “internal files exfiltrated in ransomware attack.” No inventory of file types or data categories has been published. Organisations of this kind commonly store project documentation, financial records, and communications with clients and contractors. The precise contents of the exfiltrated material have not been confirmed.

What's at stake

Exposure of internal files can create secondary risks for clients whose project details become public. These may include competitive information, site-specific security considerations, or contractual terms. For the firm, the incident adds operational costs related to investigation, notification, and potential remediation. Individuals named in the files face the standard uncertainties that accompany any uncontrolled release of professional records.

If your data was in this claimed breach

Organisations and individuals who have worked with Montalba Architects can take measured steps to limit further exposure. Concrete actions include:

• Monitoring email and postal addresses associated with past projects for unusual activity.
• Reviewing account statements and credit reports for signs of misuse.
• Running a free exposure scan of email addresses against known breach data sets to check for prior appearances.
• Contacting the firm directly for any official notification or guidance it may issue.

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