The provided text from mrd0x.com describes a method for covertly capturing screenshots from a user's computer using Chromium-based web browsers like Chrome or Edge. It explains how a specific command-line flag, --auto-select-desktop-capture-source=Entire, can bypass the typical user prompt for screen sharing, allowing a malicious webpage to automatically access and capture the entire screen. The article details the JavaScript and PHP code required to take screenshots, convert them to images, and upload them to a remote server. Furthermore, it explores options for hiding the browser window by running it in headless mode or positioning it off-screen to facilitate continuous, unnoticed monitoring of user activity for post-exploitation reconnaissance.