Edit: Okay I think I figured it out. Using an app called BLE Radar (F-Droid Link and Google Play link) you can scan nearby Bluetooth devices passively. You can use the app to setup filters to send notifications when specific devices or addresses are nearby.

[–] ackshewally@lemmy.blahaj.zone 3 points 5 months ago* (last edited 5 months ago) (1 children)

Yup, that's it. BLE Radar is the best app I've found so far. Someone go make a PR for playing a sound when a profile matches though...

Tasers, bodycams and holsters among other things made by Taser are constantly spamming advertising packets over BLE in order to be able to link to each other quickly (ie if a taser or gun is drawn, turn on the body cam). These devices are almost all made by one company and per the Bluetooth specification, the manufacturer ID is the first three bytes of the device ID, 00:25:DF: the address for Axon International Torture Devices.

Credit to Nullagent/rfparty for discovering the vulnerability. https://www.engadget.com/how-hackers-are-using-bluetooth-to-track-police-activity-140012717.html

A couple notes in practice: without dedicated hardware BLE advertising packets are very random, your phone can only sense one of the three advertising channels at once and it rotates though them. Additionally local band conditions (how many innocuous BLE devices are also around, WiFi, unrelated ISM stuff, other factors) can change sensitivity. BLE is a chaotic spammy protocol that likes to shout over itself. As a result, detections can happen the instant someone gets within ~100m of you, or they may not be detected for several seconds. Some departments may not even use Axon hardware at all, though the majority seem to. You may be able to use the WiGLE database to get a sense for your locale, but I haven't dug into that yet.

Further research: This has a lot of potential for protest/protected first amendment activities. As stated, the ability to cue an audio alert. Apps that can trigger audio/video recording when cops are very close (high RSSI). Apps that can alert a friend that lots of cops are very close and the user is unable to halt a countdown. Apps that can wipe/lock/turn off a phone if lots of cops are very close or around for an extended period of time (in custody).

[–] Gormadt@lemmy.blahaj.zone 0 points 5 months ago (1 children)

One thing I'm curious about is of using a micro controller with a much larger receiver would extend BLE sniffing capabilities.

Or setting up some LoRa equipped micro controllers to do sniffing in an area and syncing that data using a LoRa mesh to an active database of some kind. (Like utilize something similar to (or in fact) Meshtastic)

[–] ackshewally@lemmy.blahaj.zone 1 points 5 months ago* (last edited 5 months ago) (1 children)

Meshtastic is awesome, everyone go play with it, it's getting more accessible by the day.

There's a lot you can do on the hardware side. A device with three BLE chips supporting the appropriate modes would be able to sniff all three advertising channels at once, greatly increasing acquisition speed. High gain directional antennas would massively increase range. If you were especially squirrelly you could build in a GPS with high precision timing (~$25-100) and geolocate the packets via MLAT (https://en.m.wikipedia.org/wiki/Pseudo-range_multilateration). Moving up to a GPSDO you could start to do things like determine the speed and direction of travel of the sender.

[–] princessnorah@lemmy.blahaj.zone 1 points 5 months ago (1 children)

I'd love a community here on lemmy for Meshtastic.

[–] cypherpunks@lemmy.ml 1 points 5 months ago

I’d love a community here on lemmy for Meshtastic.

There are two:

/c/meshtastic@mander.xyz
/c/meshtastic@lemmy.ml

[–] dependencyinjection@discuss.tchncs.de 1 points 5 months ago (1 children)

Wait could I theoretically go to a UK police station or somewhere with a lot of police and pick up their MAC addresses.

Then if I were to be involved in some direct action I could get alerts that the police are nearby?

If so what device do I need to do this mobile? Like a laptop? Or one of those little orange hacker tools which the name is escapes me right now.

[–] yetAnotherUser@lemmy.ca 1 points 5 months ago

Interesting idea, but aren't most MAC addresses randomised per connection nowadays?

[–] taanegl 1 points 5 months ago

Police SSID's be wild.

[–] doubtingtammy@lemmy.ml 1 points 5 months ago

This is why I'm on Lemmy

[–] kalimari@lemmy.blahaj.zone 0 points 5 months ago (1 children)

Unfortunately, this requires your local police department to have the latest axon gear… I’ve actively sat down and listened for signals near my local police and didn’t spot any advertising beacons

[–] itslilith@lemmy.blahaj.zone 1 points 5 months ago

advertising bacons

[–] jackemled@furry.engineer 0 points 5 months ago

@ackshewally There's also D4:2D:C5 for i-PRO & a bunch for Motorola Solutions Inc. (different child company from Motorola, seems to make police hardware). Does anyone know any more OUIs? There are a few other Bluetooth police hardware manufacturers I've found that don't seem to have OUIs.

Also, does using an asterisk like that work? I've been using a regex for it & I would like to turn it into that to make it more readable.

I wish there was something better than BLE Radar for this that could search for things other than just MAC addresses & preset manufacturers.

[–] yournamehere@lemm.ee 0 points 5 months ago (1 children)

interesting.

i wrote some scripts that runs airodump ng, then clean the csv, send all beacons with timestamp to a database. this helped me to collect mac adresses for some time now and allows me to have alerts if neighbours are back from vacation (e.g. using home assistant i get notifications ob androidTV)

i did not go for bluetooth because espresence for homeassistant does that out of the box. https://espresense.com/

[–] dependencyinjection@discuss.tchncs.de 1 points 5 months ago

Curious as to why you want to know when your neighbours are back? Or actually the benefit of collecting MAC addresses in general.