Is this a fake dialog, or just the standard system sudo dialog, which used to allow app developers to show an arbitrary reason string?

If it was the standard macOS dialog, an app wouldn't have been able to snoop the password

Why do you think it snooped the password? Top comment says:

> - We never see or store your admin password. The dialog box you see is a native OS X API (i.e. made by Apple).

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