This looks like a custom Airtag which is great — but I cannot find where it exfiltrates data from an air-gapped system.

What did I overlook?

Looking at the code, looks like it advertises under a different private key for each bit in each message.

https://github.com/HouzuoGuo/hzgl-air-bridge/blob/master/web...

In this age of NFC, WiFi, BT, RFID, and everything in between, I am really not sure that the elite security concept of “air-gapping” is even meaningful or useful anymore.