New Android App Expands Flipper Zero Bluetooth Spam Attack Capabilities

A recent development in the cybersecurity domain highlights an expanding threat vector via Bluetooth Low Energy (BLE) spam attacks.

Initially, Flipper Zero users employing the Xtreme custom firmware had the exclusive capability to execute such attacks, mainly targeting Apple devices.

However, the threat landscape widened last week as the firmware developers adapted the attack for Android and Windows devices.

Flipper Zero's Initial Bluetooth Spam Attacks

Flipper Zero users with Xtreme custom firmware could unleash a BLE spam attack on Apple devices earlier. Though not included in the latest stable firmware, the attack found its way to Android and Windows devices via a development version.

This expanded capability enables a broader spam attack, annoying users with fake connection requests at fixed intervals. The attack targets "Fast Pair" on Android and "Swift Pair" on Windows to mirror the original assault on Apple devices.

Android App Broadens Attack Scope

Shortly after this adaptation, software developer Simon Dankelmann introduced an Android app named "Bluetooth-LE-Spam," effectively porting Flipper Zero's attack capabilities to standard Android devices.

This app broadcasts BLE advertisement packets, mimicking various devices to nearby Android and Windows devices. Although in the early stages, the app performs as intended, seamlessly emulating Flipper Zero's BLE spam attack.

Performance Limitations and Implications

However, a significant limitation exists. Unlike Flipper Zero, which boasts a more extended and precise transmission range, the Android app faces a bottleneck due to Android SDK constraints on the actual data broadcasted concerning the transmission (TX) power level.

This limitation affects the reception quality on targeted devices, indicating a less potent attack when executed from regular Android devices.

As per BleepingComputer, some broadcasts were effective from a few centimeters away, while others spanned several meters. The assault could render Bluetooth-connected devices like keyboards and mice unresponsive in a rudimentary form of Denial of Service (DoS) attack, underscoring the need for measures to fend off such Bluetooth spam attacks.

Protective Measures Against BLE Spam Attacks

To guard against these spam attacks, users can follow the steps below to disable specific notifications on their devices:

On Android 14 devices:

1. Open the phone's Settings menu.
2. Navigate to Connected devices.
3. Tap on Connection preferences.
4. Head to Nearby Share.
5. Disable the Show notification option.

On Windows devices:

1. Open the device's Settings menu.
2. Select Bluetooth & devices from the left-hand menu.
3. Click on Devices.
4. Scroll down to Device settings.
5. Disable the Show notifications to connect using Swift Pair option.

The emerging threat from Bluetooth spam attacks, though mainly just annoying at present, could morph into more malicious forms. As developers and malicious actors continue to exploit and expand these attack vectors, users are advised to stay vigilant and take necessary precautions to safeguard their digital environment.