by Source Defense
In today’s healthcare ecosystem, patient trust is built not just in exam rooms, but in browser sessions.
From patient portals and telehealth platforms to billing and scheduling systems, digital touchpoints have become the front line of engagement between patients and providers.
Yet as organizations expand their digital presence, a growing risk is emerging at the edge of these interactions: the browser itself.
The Hidden Risk in Every Click
Every healthcare website depends on third-party scripts such as analytics tools, marketing tags, scheduling widgets, and chatbots to deliver better user experiences. These scripts often pull in additional “fourth-party” code from other sources.
The result is a complex web of code running inside patient browsers, often outside the provider’s direct control. While your team hardens servers and encrypts databases, these browser-based scripts can quietly access or leak Protected Health Information (PHI), sometimes through compromise and sometimes through simple misconfiguration.
According to Verizon’s 2024 Payment Security Report, nearly 52,000 scripts were found running on payment pages across 7,000 merchant websites, with 40% directly accessing payment or personal data, a 50% increase in just one year. The same vulnerabilities apply to healthcare portals that handle sensitive patient information.
Recent enforcement actions show that even well-intentioned use of digital tools can result in impermissible disclosures of PHI to vendors or advertisers. Unlike a traditional breach, these leaks don’t occur in your data center. They happen in real time, inside your patients’ browsers.
When Compliance Meets Reality
The U.S. Department of Health and Human Services Office for Civil Rights (OCR) and the Federal Trade Commission (FTC) have made it clear: using tracking technologies without proper safeguards can violate HIPAA. Several high-profile investigations and multimillion-dollar settlements highlight that compliance risk now extends beyond your network to your digital ecosystem.
For risk, compliance, and security leaders, the message is unmistakable: compliance isn’t only about what happens on your servers. It’s about what your patients’ browsers are doing when they interact with your brand.
Why Traditional Tools Fall Short
Some organizations attempt to manage these risks using Content Security Policies (CSP) or Subresource Integrity (SRI). While both have their place, they were designed for static websites, not the dynamic, data-rich environments of modern healthcare portals.
CoalFire’s independent review of client-side controls found that these methods “require constant monitoring and updates” and “can introduce significant operational overhead”. VikingCloud reached a similar conclusion, noting that CSP and SRI “may result in over-blocking legitimate resources or under-blocking malicious content,” making them unsuitable as primary defenses against client-side attacks.
These limitations leave healthcare organizations exposed to threats that can’t be detected or mitigated by server-side or static browser controls alone.
A New Layer of Defense: Client-Side Security
Client-side security focuses on monitoring and controlling the behavior of scripts executing in the user’s browser. Rather than relying on static whitelists or manual policies, behavior-based protection continuously analyzes script activity in real time, learning which scripts access sensitive data and preventing unauthorized actions before PHI is exposed.
This proactive approach provides visibility and control that traditional defenses can’t match, helping healthcare organizations identify and stop data leaks before they occur.
Source Defense: Bringing Control Back to the Browser
Healthcare organizations are increasingly turning to Source Defense Protect, the industry’s leading behavior-based client-side security platform.
Source Defense gives you continuous visibility into every first-, third-, and fourth-party script running across your patient-facing websites. It automatically categorizes and scores each script by risk level, allowing you to apply intelligent, real-time policies such as monitor, redact, isolate, or block.
Independent assessments confirm the platform’s effectiveness. VikingCloud’s technical review found that Source Defense Protect, when configured in Redacted or Isolated modes, met PCI DSS 4.0.1 requirements 6.4.3 and 11.6.1. CoalFire’s analysis reached the same conclusion, highlighting Source Defense’s ability to “detect and prevent unauthorized behaviors” in live web environments.
For HIPAA-regulated entities, these capabilities directly support compliance with OCR’s tracking technology guidance by ensuring that PHI isn’t impermissibly shared through web interactions. They also simplify documentation for PCI DSS and other frameworks where control of third-party scripts is a core requirement.
Most importantly, Source Defense enables healthcare security and compliance leaders to move beyond checkbox compliance, empowering them to actively protect patient data, reduce third-party risk, and maintain digital trust.
Every Click Matters
The browser may be the most overlooked part of your security stack, but it’s also where patient trust lives or dies. With the right visibility, controls, and technology, healthcare organizations can finally secure sensitive data where it’s most vulnerable: in the patient’s browser, at the point of input.
PCI DSS 4.0 makes client-side security a priority.
Source Defense delivers a solution for 6.4.3 and 11.6.1 without adding a burden to your security teams.