- Add trusted CA certificates.
- Configure proxy settings.
- Launch arbitrary applications.
- Delete all the users files.
What you're talking about here is sandboxing to protect the user from themselves, and all the lost utility that results. In other words, iOS.
- Configure proxy settings: prompt for admin credentials
- Launch arbitrary: already admitted as much
- Delete all users files: yup, that's a problem
But the problems I illustrated aren't limited to the single machine that gets infected.
Just clarifying.
You've already social-engineered your way to getting somebody to download and run an application, ignoring warnings along the way. Prompts for credentials when installing applications are perfectly normal.
> Configure proxy settings: prompt for admin credentials
??? Not on my machine. There isn't even a padlock icon in the relevant window.
IIRC this isn't protected by the actual keychain file, and can be done by simply editing the file manually.
Regardless, peer commentator already noted that password prompts are hardly an issue here.
> - Configure proxy settings: prompt for admin credentials
Actually, it doesn't. Additionally, browsers have per-user local configuration.