IBM Guardium by IBM Guardium

The IBM Guardium browser extension for Firefox helps organizations that use IBM Guardium Exposure Manager to mitigate sensitive data exposure.
The extension monitors browser-based file operations on supported websites, including uploads, downloads, drag-and-drop, and paste events, and enforces security policies in real time to prevent data exfiltration.
The extension communicates securely with the locally installed IBM Guardium Exposure Manager native agent by using Native Messaging, which uses AES-GCM encryption and RSA-OAEP key exchange. All data processing and browser-to-agent communication occur locally on the device. The extension does not transmit browsing history, page content, or user data to any remote service.