Petaluma Health Center Breach Incident Score: Analysis & Impact (TRIOCHPET1769201334)

In this Rankiteo incident briefing, we review the Petaluma Health Center breach identified under incident ID TRIOCHPET1769201334.

The analysis begins with a detailed overview of Petaluma Health Center's information like the linkedin page: https://www.linkedin.com/company/petaluma-health-center, the number of followers: 2450, the industry type: Hospitals and Health Care and the number of employees: 311 employees

After the initial compromise, the video explains how Rankiteo's incident engine converts technical details into a normalized incident score. The incident score before the incident was 726 and after the incident was 669 with a difference of -57 which is could be a good indicator of the severity and impact of the incident.

In the next step of the video, we will analyze in more details the incident and the impact it had on Petaluma Health Center and their customers.

On 15 December 2025, Petaluma Health Center disclosed Data Breach issues under the banner "Petaluma Health Center Data Breach Exposes Sensitive Patient Information".

Petaluma Health Center recently disclosed a data breach affecting sensitive personal and health-related information of its patients.

The disruption is felt across the environment, affecting TriZetto's system (third-party vendor for OCHIN), and exposing Sensitive personal and health-related information.

In response, and began remediation that includes Notification to affected individuals, complimentary credit monitoring services, and stakeholders are being briefed through Mail notifications to affected individuals, breach notice filed with California Attorney General’s office.

The case underscores how Ongoing, with advisories going out to stakeholders covering Mail notifications to affected individuals.

Finally, we try to match the incident with the MITRE ATT&CK framework to see if there is any correlation between the incident and the MITRE ATT&CK framework.

The MITRE ATT&CK framework is a knowledge base of techniques and sub-techniques that are used to describe the tactics and procedures of cyber adversaries. It is a powerful tool for understanding the threat landscape and for developing effective defense strategies.

Rankiteo's analysis has identified several MITRE ATT&CK tactics and techniques associated with this incident, each with varying levels of confidence based on available evidence. Under the Initial Access tactic, the analysis identified Trusted Relationship (T1199) with high confidence (90%), supported by evidence indicating unauthorized individual had accessed a system belonging to TriZetto, a third-party vendor. Under the Credential Access tactic, the analysis identified Steal Application Access Token (T1528) with moderate to high confidence (70%), supported by evidence indicating accessed a system belonging to TriZetto, a third-party vendor working with OCHIN and Valid Accounts (T1078) with moderate to high confidence (80%), supported by evidence indicating unauthorized individual had accessed a system (implies valid credentials or tokens). Under the Collection tactic, the analysis identified Data from Local System (T1005) with high confidence (90%), supported by evidence indicating patient data...includes names, SSNs, dates of birth, health/insurance data. Under the Exfiltration tactic, the analysis identified Exfiltration Over C2 Channel (T1041) with moderate to high confidence (80%), supported by evidence indicating data breach affecting sensitive personal and health-related information and Transfer Data to Cloud Account (T1537) with moderate confidence (60%), supported by evidence indicating third-party vendor system compromise (could imply cloud exfiltration). Under the Impact tactic, the analysis identified Data Destruction (T1485) with lower confidence (30%), supported by evidence indicating no evidence of destruction, but breach implies potential risk and Data Manipulation: Transmitted Data Manipulation (T1565.002) with lower confidence (40%), supported by evidence indicating health-related data exposed (could be altered or misused). These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.