Marin Cancer Care Data Breach
Marin Cancer Care learned on or about December 8, 2025, that its computer network had been accessed without authorization.
Key points
- Unauthorized network access discovered on or about December 8, 2025.
- Access occurred between November 22, 2025, and December 6, 2025.
- Patient information, medical information, and health insurance information potentially exposed.
Connected intelligence
Signal brief
Follow the organization, likely method and potential impact to explore connected Shadow Tier intelligence.
Organization
- Published
- Dec 8, 2025
- Updated
- Jun 25, 2026
- Confidence
- Medium
- Evidence
- 3 sources
Structured assessment
Signal analysis
This analysis groups the signal by industry, likely incident action and impacted security area. It helps compare this signal with other published signals without treating the labels as final determinations.
Threat source
Watch internet-facing systems, credential abuse and exploit activity.
Business impact
- Impact area
- Confidentiality
- Likely asset
- User or customer data
Mentioned entities
Quick context
Questions about this signal
What happened in this signal?
Marin Cancer Care learned on or about December 8, 2025, that its computer network had been accessed without authorization. The unauthorized access occurred between November 22, 2025, and December 6, 2025. Files containing patient information, including names, medical information, and health insurance information, may have been viewed or acquired.
When was this signal reported?
Shadow Tier lists Dec 8, 2025 as the signal date.
Which organization is connected to this signal?
Marincancercare is the organization connected to this public signal.
Explore MarincancercareRelated signals
Compare shared topics, actors and incident patterns before opening the full signal.
Xsolis Data Breach Exposes 1.4 Million Patient Records Across Eight Health Systems
A targeted phishing attack on healthcare AI company Xsolis has exposed the data of at least 1.4 million patients across eight U.S. health systems. Xsolis develops utilization management and care coordination technology widely used by hospitals and health systems. This breach now ranks among the most significant healthcare vendor cyberattacks of 2026. The U.S. Department of Health and Human Services (HHS) confirmed the patient impact figure on June 22, after Xsolis filed its breach report on June 5. Moreover, legal action over the incident has already been filed in at least one case, signaling growing accountability pressure on AI vendors handling sensitive patient data. The breach did not begin with the disclosure. Instead, the unauthorized access occurred months earlier. On January 20, 2026, an unidentified actor accessed portions of Xsolis’s IT environment. The attacker then acquired a limited number of files from within the system. Xsolis did not report the incident to HHS until June 5 — roughly four and a half months after the initial intrusion. This delay has drawn scrutiny. Furthermore, Hendrick Health in Abilene, Texas, faced a separate lawsuit specifically citing delayed patient notification as a key concern. Xsolis has stated the company is not currently aware of any misuse of the stolen data. However, the company has declined to specify which types of patient information were exposed. A spokesperson confirmed Xsolis is notifying affected individuals but is not commenting beyond its June 5 public statement. The following health systems have confirmed involvement in the Xsolis data breach : Rochester Regional Health — Rochester, N.Y. Together, these eight organizations collectively serve patients across six states. Consequently, the breach spans a wide geographic footprint — from the Pacific Northwest to the Southeast and Midwest. Xsolis took several steps after discovering the breach . First, the company reported the incident to HHS on June 5. Next, it began notifying affected patients directly. Additionally, Xsolis released a formal public statement through PR Newswire acknowledging the security incident. However, critics note that the five-month gap between the January intrusion and the June disclosure raises serious questions. Under HIPAA, covered entities and business associates generally must report breaches within 60 days of discovery. Health systems and regulators are now examining whether this timeline met legal standards. Why This Breach Matters for Healthcare AI This incident highlights a critical vulnerability in modern healthcare operations. Health systems increasingly rely on third-party AI vendors for functions like utilization management and care coordination. As a result, these vendors hold highly sensitive patient records — making them attractive targets for cybercriminals. Phishing attacks remain the leading method hackers use to gain unauthorized access. Notably, a single successful phishing email at a vendor like Xsolis can cascade into a breach affecting millions of patients at multiple health systems simultaneously. Third-Party Risk in Healthcare Is Growing Third-party vendor breaches now account for a rising share of healthcare data incidents. Therefore, health systems that outsource clinical and operational functions to AI companies must treat vendor cybersecurity as a direct extension of their own risk management. Regulators, including HHS’s Office for Civil Rights, actively scrutinize business associate agreements (BAAs) and breach timelines. Health systems found to lack adequate vendor oversight face fines and reputational harm alongside their vendors. Health system leaders should act quickly when a vendor breach occurs. First, they must verify whether their organization was part of the affected vendor’s client base. Next, they should request a full incident report from the vendor, including the timeline and scope of data access. Additionally, health systems must assess their own HIPAA obligations independently. Even when a vendor like Xsolis handles patient notifications, the covered health system retains compliance responsibility. Going forward, health systems should strengthen third-party risk programs. Key actions include conducting annual security assessments of all AI and health IT vendors, requiring vendors to carry cyber liability insurance, and including clear breach notification timelines in every BAA. Furthermore, phishing awareness training must extend beyond a health system’s own staff. Health systems should require vendors to demonstrate regular employee security training as a contract condition. Ultimately, a vendor’s security posture directly affects every patient record that vendor touches. Vendor breaches, regulatory shifts, and the governance gaps in between. Here's what happened this month in third-party risk management news. Financial institutions are legally accountable for what their vendors do with customer data. Outsourcing a function doesn't outsource the liability that comes with it — a principle that runs through GLBA Safeguards Rule requirements, state privacy laws, and open banking obligations under Part 1033. Vendor contracts need to do more than check a compliance box: they should specify permitted data uses, require breach notification within 24–48 hours, include audit rights, and address AI governance for any vendor using automated decision-making. Fourth-party risk also warrants explicit contract language requiring vendors to disclose and flow down obligations to their own subcontractors. A phishing attack on a healthcare AI vendor exposed 1.4 million patient records. Xsolis, which provides AI-powered utilization management to hospitals and health insurers, was breached through a single phishing email, exposing Social Security numbers, health insurance details, and medical treatment records across seven major hospital systems including Mayo Clinic. At least one organization — Rochester Regional Health — had ended its relationship with Xsolis in 2021, yet its patient data was still in scope at the time of the breach. Most of the 1.4 million affected had no idea the vendor held their information at all. Third-party vendor incidents now account for 58% of all healthcare data breaches, and this case is a concrete reminder that data deletion at offboarding is a risk control, not an administrative afterthought. The Klue breach reached LastPass customer data. Attackers used OAuth tokens stolen from Klue to access LastPass's Salesforce environment, exposing customer names, contact details, and support case records. Password vaults were unaffected, but the stolen data is enough to fuel targeted phishing. Fourth-party risk in practice: a vendor relationship several steps removed still produced direct customer harm. How to Avoid Common Third-Party Risk Management Mistakes
Related context
Aflac Life Insurance Japan Suffers Cybersecurity Breach Exposing Policyholder Data
Aflac Life Insurance Japan disclosed unauthorized access to its systems between June 15 and June 25, 2026. The breach affected files containing policy details, personal information, and bank account information of approximately 4.38 million customers. The company has suspended affected systems and is investigating the incident with third-party cybersecurity experts.
Related context
National Association of Insurance Commissioners (NAIC) Confirms Data Breach via Oracle PeopleSoft Zero-Day
The National Association of Insurance Commissioners (NAIC), a US insurance regulatory standards body, confirmed a cyberattack after the ShinyHunters group claimed theft of 3.1TB of data. The breach was reportedly achieved through an Oracle PeopleSoft zero-day vulnerability. ShinyHunters claimed access to regulatory filings, production logs, cloud configuration files, and other internal records.
Related context
Trenitalia Suffers Cyberattack, Customer Data Compromised
Trenitalia, the Italian state-owned railway company, notified customers on June 26, 2026, about a cyberattack that led to unauthorized access of personal data related to travel tickets. The company detected the incident through internal checks and attributed it to 'unidentified external parties.' The attack itself reportedly occurred in November 2025. Compromised data included demographic and identification details, contact information, travel specifics, and loyalty card numbers, but no payment information or account credentials were affected.
Related context
Origin Energy Discloses Data Breach Affecting 900,000 Customers
On July 28, 2026, Origin Energy, a major Australian energy company, publicly confirmed a significant data breach impacting approximately 900,000 current and former customers. The breach led to unauthorized access and exfiltration of personally identifiable information (PII), including names, addresses, dates of birth, phone numbers, account details, and partial payment information such as the last four digits of credit cards or the BSB and last three digits of bank accounts. Origin Energy first identified a potential security threat in early July 2026, which was initially not deemed credible. However, new information on July 22, 2026, confirmed a security incident had occurred, prompting immediate action and notification of authorities. An alleged hacker provided a media outlet with a sample of 50 customer records and screenshots of internal Origin Energy systems, corroborating the data exfiltration. The incident is currently under investigation by Australian authorities, including the Australian Cyber Security Centre, the National Office of Cyber Security, the Australian Federal Police, and the Office of the Australian Information Commissioner. The specific technical vector used for initial access remains undisclosed.
Related context
South Korean Domain Registrar Gabia Hacked, Exposing 350,000 User Records
South Korean domain registrar Gabia experienced a cyberattack on Saturday, July 26, 2026, which impacted the online connectivity of approximately 100,000 registered domains. The incident led to the exposure of data belonging to 350,000 users. The compromised information included names, user IDs, passwords, and registration numbers. This breach highlights the significant risks associated with compromised credential reuse, as a large portion of the exposure originated from "Combolist sources." Additionally, active infostealer activity, linked to malware families such as LummaC2, Redline, and Rhadamanthys, was identified, further indicating a focus on credential theft impacting both clients and employees. The incident also revealed 245 compromised employee accounts, posing an infrastructure risk, and 30,782 leaked client credentials, creating regulatory liability. The timeline of related events showed an increase in client-related incidents from August 2025 through April 2026, with a peak in March 2026, and spikes in employee-related events in January, April, and May 2026. Remediation efforts should prioritize credential hygiene, multi-factor authentication enforcement, and enhanced monitoring for suspicious login activity, particularly targeting login forms and account management services. The incident was reported by the Korea Herald on Monday, July 28, 2026.