The Silent Exfiltration
Google Chrome supports an advanced API known as the Async Clipboard API. By default, websites must ask for permission to read from your clipboard, but many sites can aggressively attempt to hijack it. If you copy a sensitive password from your password manager, a malicious website running a rogue script could attempt to silently read that text the moment you focus on the tab. Alternatively, websites can maliciously overwrite your clipboard, tricking you into pasting a fraudulent cryptocurrency address instead of the one you intended. To guarantee total security, you must paralyze this API.
How to Block Clipboard Access Globally
You can permanently sever the browser’s ability to interface with your system clipboard via Chrome’s Site Settings.
- Open the Google Chrome desktop browser.
- Click the three vertical dots (⋮) in the top right corner and select Settings.
- In the left-hand sidebar, click on Privacy and security.
- In the main window, click on Site settings.
- Scroll down to the “Permissions” heading and click to expand Additional permissions.
- Click on Clipboard.
- Under the “Default behavior” heading, select the radio button for “Don’t allow sites to see text or images on your clipboard.”
Total Memory Isolation
The change takes effect instantly. Google Chrome will completely sever its internal connection to your operating system’s global clipboard buffer. The browser is now permanently blind to what you have copied to memory. If a website attempts to execute a script to silently read your clipboard contents, the API call will instantly auto-reject in the background. You can still manually highlight text and press Ctrl+C or Ctrl+V, as those are handled by the core operating system, but background web scripts are permanently blocked from reading or writing to your memory.