The report explains that EDR solutions primarily detect malicious activity through endpoint telemetry such as process execution and persistence mechanisms. However, many modern attacks leverage browser sessions and SaaS workflows that do not produce these endpoint artifacts. Examples include adversary-in-the-middle phishing campaigns that intercept OAuth tokens and session cookies, malicious Chromium extensions that harvest browsing data and send it to attackers, and attacks that manipulate browser content or clipboard data to trick users into executing commands. These attack vectors bypass EDR visibility because they operate entirely within the browser context or cloud applications. The report cites specific incidents such as the 2025 Salesloft Drift incident and the 2026 Microsoft-observed Storm-2755 phishing campaign. It advocates for browser-level security controls to complement EDR, including blocking phishing sites, managing extension permissions, and restricting clipboard and file transfer actions within the browser.

Browser-based attacks can lead to credential theft, unauthorized access to cloud services, data exfiltration, and eventual host compromise without triggering traditional EDR alerts. This gap allows attackers to operate stealthily within SaaS environments and browser sessions, potentially accessing sensitive corporate data and identity workflows. The lack of endpoint artifacts means that many attacks go undetected by endpoint telemetry alone, increasing the risk of prolonged undetected breaches.

The vendor advises that EDR remains essential for detecting host-level execution but is insufficient alone to detect browser-based threats. Organizations should deploy browser-level controls such as phishing protection to block malicious sites, extension allowlists and permission reviews to prevent malicious extensions, and restrictions on clipboard and file transfer actions within browsers. Using phishing-resistant authentication methods like FIDO2 WebAuthn can prevent adversary-in-the-middle phishing attacks. These measures help detect and block attacks before they reach the endpoint execution stage where EDR can intervene.