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Find You: Building a stealth AirTag clone

positive.security

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Re: Find You: Building a stealth AirTag clone

#31

Post by Scoundreller »

Friday_ wrote: post #29
Scoundreller wrote: post #18

Earlier quoted context omitted.

There are some groups building 'armageddon' mesh-based hand-held communicators like Meshtastic. Converged hardware is already there. The network probably is too in more and more metros if you're not within a few km of what you're trying to communicate with/track. https://meshtastic.org Map: https://canvis.app/meshtastic-map

This looks interesting, but device itself looks like it wouldn't survive fall on the floor, let alone armageddon. Just joking.

The case is up to you. I plan on using a plastic food jar :)

Re: Find You: Building a stealth AirTag clone

#32

Post by Friday_ »

giaour wrote: post #19
Friday_ wrote: post #6

Why not build your own tracker that doesn't rely on Apple. You only have to have GPS, LoRaWAN, MCU, battery, and antenna, That's about it.

Can you get onto a lorawan network without some kind of service contract? Seems like it would leave a paper trail for investigators to follow, whereas the pirate AirTags described in the article are anonymous commodity hardware using the victim's Apple devices for connectivity.

I don't know. Maybe you get signal from tracker ( everyone likewise ) and if somebody ask you if you are the owner of it, you just play dumb.

Re: Find You: Building a stealth AirTag clone

#33

Post by kayson »

LeoPanthera wrote: post #25
rahimnathwani wrote: post #20

Earlier quoted context omitted.

Because: - using a cellular modem requires a high capacity battery - if you hide a tracker well, it probably won't have a good GPS reception Apple's BLE-based network solves both of these problems.

> using a cellular modem requires a high capacity battery The example third party AirTag clone described on the linked page is powered by a full size USB power bank.

Because it's a proof of concept using an ESP32, not because that battery capacity is fundamentally necessary for the idea to work.

It could easily be optimized for power and size. Sure, it will have to use more power than a vanilla airtag, because it's doing (slightly) more, but not enough to make a significant difference.

Re: Find You: Building a stealth AirTag clone

#34

Post by UncleEntity »

IshKebab wrote: post #30
mmastrac wrote: post #16

Does this mean that Apple is failing to validate the capability of things that purport to be AirTags? Or that the BLE protocol is just not powerful enough to have Apple signatures on each broadcast public key? If it's the latter, it might mean that the entire AirTag product line is dead in the water.

Yeah I don't understand this. Surely airtags have to be registered, and when an iPhone sees tag 3957375967 Apple's servers look that up and say "oh it's registered to Billy Bob; I'll tell them". But if your fake airtag rotates through 2000 IDs how do you register them all?

Apple apparently stores every reported location in a database and allows people to query whether a certain public key was received with or without the key being registered to a specific user since they change on a regular basis so one can’t track a specific device.

Re: Find You: Building a stealth AirTag clone

#37

Post by deanc »

smithza wrote: post #21
mmastrac wrote: post #16

Does this mean that Apple is failing to validate the capability of things that purport to be AirTags? Or that the BLE protocol is just not powerful enough to have Apple signatures on each broadcast public key? If it's the latter, it might mean that the entire AirTag product line is dead in the water.

Apple will probably say something to the effect of, "we didn't have to put anti-stalking technology in, and it works well for the 99% of use cases." The common stalker will not have the technical skills to build their own custom-firmware version of a BLE-enabled system. I don't think this revelation will kill the product line.

I didn't fully grep the article, but assuming the src is public and hardware is trivially built - I wouldn't put it past someone packaging this up and selling it. It doesn't need a huge number of people to be bad enough PR for Apple to have to do something - much like 99.9999999% of people are not using them for stalking but it's all that's talked about in the media with these tags.

Re: Find You: Building a stealth AirTag clone

#38

Post by anchpop »

mox1 wrote: post #26
smithza wrote: post #24

Earlier quoted context omitted.

It is a difficult technical problem for Apple to solve all of the corner-cases. The article shows the screenshot of seemingly 100 unique FindMy devices around this guy's personal residence... there may be some characterization work that can help solve that so an iPhone user would get the alert message. But Apple will continue to promote it and dismiss or downplay these security concerns.

The problem is easy to solve, just store copies of all public keys of each air tag you send out. Air Tag messages with unknown public keys just get dropped on their server side checks.

A core selling point of Airtags is that other people's iPhones help you find your AirTag. That's also what makes them effective trackers. It's a bit of an unsolvable problem.

Re: Find You: Building a stealth AirTag clone

#39

Post by moffkalast »

eyeeyesawayyy wrote: post #23
noja wrote: post #3

Other trackers don't tell you they are tracking you though, what about those.

Airtags are unique in that they use every iphone in the world as part of the network which tracks them and reports their locations. So, unlike GPS trackers or competing Bluetooth trackers, AirTags can do two things: * Last for a very long time on a small battery, no recharging required. * Reliably report location anywhere in the world that an ordinary person is likely to be.

I've always been sceptical of this working well enough to be usable. Does the average iphone owner leave their bluetooth, gps, and mobile network on 24/7? Sounds like an awful waste of power. What about in the rest of the world outside the US, Canada and Australia where Android is the market leader and iphones are rather rare?

What happens inside buildings when the phone doesn't have a fix? Does it store the tag's key and sends it as soon as it gets gps data?

Re: Find You: Building a stealth AirTag clone

#40

Post by mox1 »

anchpop wrote: post #38
mox1 wrote: post #26

Earlier quoted context omitted.

The problem is easy to solve, just store copies of all public keys of each air tag you send out. Air Tag messages with unknown public keys just get dropped on their server side checks.

A core selling point of Airtags is that other people's iPhones help you find your AirTag. That's also what makes them effective trackers. It's a bit of an unsolvable problem.

Yes, and Apple 100% has the capacity / ability to filter out "fake" AirTags on their back-end. All they need to do is setup a manufacturing process that captures the public keys.

So the phones will still relay the beacons to Apple, who can then do things and just reject messages from these fake tags.

(I worked for a Medical Device Company that set all of this up within our supply chain).

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