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

On November 23, 2025, the sinobi ransomware group listed Advanced Dental of Aliso Viejo, California, on its leak site and claimed to have exfiltrated internal files during a ransomware attack. The number of people whose information may be involved is not known, and no further details about the scope or contents of the material have been made public. The incident is significant because dental practices routinely store sensitive personal and health information. Any confirmed exposure of such records can affect patients’ privacy and create downstream risks that are difficult to reverse.

Inside the incident

Public reporting on the event is limited to the group’s listing of Advanced Dental and the statement that internal files were taken. No confirmation of the listing, no description of the intrusion method, and no timeline of when the access occurred have been released by the organization or by investigators. The scale of the data removal also remains undisclosed.

The group behind it: sinobi

Sinobi is a ransomware operation that maintains a public leak site where it lists organizations it claims to have targeted. The group typically pairs file encryption with data exfiltration and then posts samples or directories of stolen material to pressure victims. Its listings are presented by the group itself; independent verification of each claim is not always available at the time of posting.

Advanced Dental and its sector

Advanced Dental provides laser dentistry, implants, Invisalign, emergency care, and general services to patients of all ages in Aliso Viejo, California. Dental practices collect and retain records that include patient identifiers, treatment histories, insurance details, and billing information. Because these organizations are smaller than hospital systems, they may have fewer dedicated security resources while still holding data that is valuable for identity theft or insurance fraud.

What data was at risk

The only information released states that internal files were exfiltrated. The precise categories of data within those files have not been disclosed. Organizations of this type commonly hold names, addresses, dates of birth, Social Security numbers, medical histories, insurance policy numbers, and payment details, but it is not confirmed whether any of these specific elements were among the material taken in this case.

The real-world impact

Individuals whose records appear in the exfiltrated files could face risks of identity theft, targeted scams, or misuse of health information. The organization may incur costs related to investigation, notification, and remediation. Because the volume and sensitivity of the data remain unknown, the full extent of these consequences cannot yet be measured.

If your data was in this claimed breach

Monitor bank and insurance statements for unusual activity and consider placing a fraud alert or credit freeze with the major credit bureaus. Contact Advanced Dental directly for any official notices it may issue. Readers can also run a free exposure scan of their email address against known breach data sets to check for prior appearances of their information.

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