Security researcher highlights macOS remote exploit w/ custom URL schemes
Security researchers look at how macOS users can be remotely targeted using document handlers and custom URL schemes – which is behind the “Do you want to allow” popup seen in the above screenshot.
Patrick Wardle explains how a custom APT abuses URL schemes to remotely infect macOS targets
On macOS, applications can “advertise” that they can support (or ‘handle’) various document types and/or custom URL schemes. Think of it, as an application saying, “hey if a user tries to open a document of type foo or a url with a scheme of bar I got it!”
You’ve surely encountered this on macOS. For example when you double click a .pdf document Preview.app is launched to handle the document. Or in a browser you click a link to an application which lives in the Mac App Store, the App Store.app is launched to process that request.