According to our information, the reseller did not distribute official GrapheneOS. Using AI tools, he had built his own fork and added mobile device management (MDM) for remote administration. The result was a separate operating system that lacked, among other things, the security updates of the original project.

His signing keys for that system were probably compromised. Anyone holding those keys can build an update that the phones accept as genuine. Such an update was apparently installed on seized phones via ADB (Android Debug Bridge), an interface that requires a USB cable connection, and probably removed the screen lock. The phones could then be examined forensically. On our information, the authorities again needed the phone in their hands. On official GrapheneOS, the same approach would require the project's own signing keys.

https://www.joint-defense-team.com/post/grapheneos-cracked-p...