They have one already. The questions here is with the malware now being over a year old and already abadoned by its creator:
1. Why are we getting an alert about it from these researchers only now?
2. Why hasn't Apple blocked it already?
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I feel like the real issue here that nobody has brought up (not just here, but anywhere) is why is the admin account as required and powerful as it is?
It seems like there's a massive failure of properly designing permissions. Why does an admin account have read access to all of the stuff this malware steals? It seems like the only thing that should ever be able to access my browser data on my personal computer is the browser when I'm using it - there shouldn't be an admin account that can bypass that and read the data.
IDK - all of *nix permissions feel dated and improper for usage on personal computers. IDK how permissions work on Windows... do they make more sense over there?
As much as I hate how security and the filesystem works on iOS... I am starting to see the appeal... and honestly, I don't think it goes far enough. All files that an app on iOS saves shouldn't just be sandboxed so that other apps can't read it, but they should be encrypted such that not even any system or admin account can read it - only the app that made it should be able to decrypt and read it. Getting "root" or admin access shouldn't be as big of a deal as it is...
Tell me you know nothing about security in macOS without telling me.
I wonder what reaction there would be if Apple removed access to your own browser data.
This "malware" works because the user allows the process to access the data, running as the logged in user. The malware is started by the user, then asks for the users password. By typing it in, the user has given the process access to their password, which then can be used to access data where macOS requires a password.
This is why you don't type your password in shady-looking dialogues!
Your suggestion that all data should be sandboxed and not accessible by other applications would make macOS impossible to use in any productive way. The power of macOS is in fact the possibility to access the same data with different applications. This is by far the most asked for feature that iPadOS (and iOS) lacks at the moment.
Unix permissions are more or less just for show nowadays. SIP and TCC makes it extremely difficult to access data, even as "root" (which by the way is also quite difficult access, if even possible) but if the user types in their password, and mind you they don't even have to have admin rights they can be a "standard user", macOS of course grants access to the users data.
This is in no way different from how security works on Windows. If you grant an application access to your data, it will have access to your data. In fact, macOS has a lot more guardrails to ask the users if they really want to grant access.