What is FluBot (Cabassous) malware's unique distribution mechanism and what made its spread particularly rapid?

• A.C) FluBot used Bluetooth proximity to spread to nearby Android devices; no human interaction was required.
• B.B) FluBot spread exclusively through official app stores; it evaded Play Protect by using multiple dropper stages.
• C.A) FluBot spread via SMS messages claiming to be package delivery notifications with a link to a fake tracking app; once installed, it accessed the victim's contact list and sent the same SMS to all contacts from the victim's number, creating an organic peer-to-peer propagation chain. This made it appear as messages from trusted friends/family, dramatically increasing click-through rates compared to random-number spam campaigns.
• D.D) FluBot propagated by exploiting an unpatched RCE vulnerability in Android's SMS handling; no user interaction was needed.