Was Petaluma Health Center hit by ransomware?

Petaluma Health Center was listed by the Karakurt ransomware operation (United States), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the Karakurt ransomware group?

Karakurt is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the Petaluma Health Center breach?

Karakurt published data attributed to Petaluma Health Center (~490 GB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Petaluma Health Center

Claimed by Karakurt · listed 3 years ago

490 GB

Data size

39m

Age

since listed · data leaked

Status timeline

ListedApr 12, 2023
Data leakeddate unknown

At a glance

Group: Karakurt
Status: Data leaked
Country: United States
Sector: Healthcare
Listed on leak site: Apr 12, 2023
Data size: 490 GB

About the victim

AI dossier — public-source company profile

Petaluma Health Center is a Federally Qualified Health Center (FQHC) based in Petaluma, California, operating multiple clinic locations across Sonoma and Marin counties including sites in Rohnert Park, Point Reyes, and Bolinas. The organization provides comprehensive primary and specialty care services — including family medicine, behavioral health, dental, HIV care, pediatrics, and school-based health — to all patients regardless of ability to pay. It serves vulnerable and underserved populations including homeless shelter clients and high school students.

Industry: Federally Qualified Health Center (Community Health)
Address: Petaluma, California, United States

Attack summary

Severity: critical — Confirmed exfiltration and publication of 490 GB of data from a healthcare provider, including protected health information (PHI), patient medical records, and employee PII (SSNs, passports) at scale — squarely meeting the critical threshold for regulated medical and personal data exposure affecting a vulnerable patient population.

Karakurt claims to have exfiltrated approximately 490 GB of data from Petaluma Health Center, including patient personal and medical information, financial documents (declarations, payment records, tax forms), and employee personally identifiable information such as SSNs, passport details, phone numbers, and addresses. The group has published the data (disclosed status: data_published).

critical

Data the group says was taken

AI dossier — extracted from the leak post

Patient personal information
Patient medical records
Financial declarations
Payment documents
Tax forms
Employee SSNs
Employee passport copies
Employee phone numbers
Employee addresses

What the group claims

The Petaluma Health Center is a Federally Qualified Health Center that strives to care for the "whole" individual by providing excellent care for all patients, regardless of one's ability to pay for services. We do not know whether their patients personal and medical information was stored unsafely because of their disability to pay but we have almost 490GB of this Health Center on our servers. Along with that we've obtained a good amount of financial information (numerous declarations, payment docs, tax forms ...) and personal employees information (SSNs, passports, phone numbers, addresses etc).That is going to be interesting.

Sources

Victim sitephealthcenter.org

Source

Indexed 3 years ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.

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Disclosure context

About Karakurt

Karakurt is a ransomware group that emerged in December 2022, operating primarily as a data extortion threat actor with financial motivations rather than traditional file encryption. The group's origin and affiliations remain largely undocumented by major cybersecurity agencies, though their operational patterns suggest they function as an independent entity rather than a confirmed ransomware-as-a-service operation. Karakurt employs data theft and extortion tactics, focusing on exfiltrating sensitive information from victim networks before demanding payment under threat of public disclosure, representing a pure extortion model that bypasses traditional encryption-based ransomware approaches. The group has targeted 74 known victims across multiple sectors, with particular focus on healthcare, education, manufacturing, energy, and professional services organizations, primarily affecting entities in the United States, United Kingdom, Germany, Singapore, and India. Based on available reporting from established cybersecurity agencies and researchers, Karakurt appears to remain active as of recent assessments, though comprehensive intelligence on their specific attack vectors, tools, and major campaigns remains limited in publicly documented sources from CISA, FBI, and major security research organizations. The group has been linked to 74 public disclosures across our corpus. First observed on a leak site on December 11, 2022; most recent post September 22, 2023. The operation is currently inactive.

Timeline of this disclosure

April 12, 2023Petaluma Health Center listed by Karakurton the group's public leak site

Data size: 490 GB

Other recent disclosures by Karakurt

Karakurt has been linked to 74 public victims on Darkfield. A sample of the most recent:

See the full Karakurt dossier →

Sector and geography

This disclosure adds to ransomware activity in the Healthcare sector, which has 2,600 disclosures indexed across all operators we track. Geographically, Petaluma Health Center is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Karakurt means Petaluma Health Center appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
Report the incident to your national CERT, CISA (United States), as required for your jurisdiction.
Monitor for the data appearing on Karakurt's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.