ExecFence catches fake-CAPTCHA "paste this command" scams and warns you before you run something dangerous in Terminal or PowerShell.
Open the live demo with ExecFence installed to see the warning fire, and the safe page to see it stay silent.
Does it slow down my browser? No — analysis is local and only runs when a page shows the scam pattern.
Does it see my passwords or what I copy? No. It never reads your clipboard and never uploads anything. See the privacy policy.
It warned on a page I trust. Click "Trust this site" in the warning, or turn on Developer mode in settings.