Occasionally an app pops up a dialog like the one pictured. Some questions regarding it.
Is it true that an app that I launch has the same permissions as me? So why does it ask me for my credentials? The creds wouldn't elevate its permissions
An app doesn’t necessarily have the same permissions as you; it all depends on what the app needs to do (i.e. installation/upgrading) when asking for your credentials. Going on the assumption you are an admin with commensurate privileges, the app may require elevated privileges to tie into the system. The changes could be anything from making changes to the PATH variable to accessing services like printing or working with physical devices like a microphone. Typically, where you see this is during the installation process where it needs write a file to a protected volume/directory that is owned by root. Adding a LaunchAgent or LaunchDaemon Is another good example. Installing software that will be available to “all users” systemwide (regardless if you actually have multiple users on that system) is also an excellent example (think Adobe Photoshop or MS Office, LibreOffice, etc.).
How would I go about finding out what resources the app is trying modify. Or, at least, what resourdces it modified after I entered credentials
Normally, this info would be found in the install log of the app in question. It could be a standalone file or it could have used the built in logging subsystem (i.e.syslog) which would, ironically, require elevated privileges to do so.
What process/daemon owns this dialog
It’s not a single process or daemon responsible for this (not sure why this is relevant). Thus, the answer here is it depends. Privilege escalation requests could be from parental controls, network security, etc. and not relegated to the core system only.
Security is a very broad topic; you may find some value in reviewing the Apple’s Guide Apple Platform Security
