[HN Gopher] SeaGlass: City-Wide IMSI-Catcher Detection (2017)
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       SeaGlass: City-Wide IMSI-Catcher Detection (2017)
        
       Author : karlzt
       Score  : 118 points
       Date   : 2023-08-23 16:12 UTC (6 hours ago)
        
 (HTM) web link (seaglass.cs.washington.edu)
 (TXT) w3m dump (seaglass.cs.washington.edu)
        
       | ta8645 wrote:
       | An explanation wasn't prominently displayed on that web site, so
       | from https://en.wikipedia.org/wiki/IMSI-catcher :
       | 
       | An international mobile subscriber identity-catcher, or IMSI-
       | catcher, is a telephone eavesdropping device used for
       | intercepting mobile phone traffic and tracking location data of
       | mobile phone users. Essentially a "fake" mobile tower acting
       | between the target mobile phone and the service provider's real
       | towers, it is considered a man-in-the-middle (MITM) attack.
        
         | H8crilA wrote:
         | How come the tower doesn't have to cryptographically
         | authenticate with the phone? Like websites do, using TLS
         | certificates.
        
         | [deleted]
        
       | h2odragon wrote:
       | 2017, code link: https://github.com/seaglass-project/seaglass
       | 
       | Pi connected to a Cell modem, mobile hotspot, and "bait phone"
       | ... and a separate GPS.
       | 
       | All powered by wall warts off an inverter to the car's 12v
       | system.
       | 
       | This makes me feel better about my own systems designs.
        
         | thedougd wrote:
         | Yeah. I went down the rabbit hole of ways to remove most of
         | those components but I guess it's easy to instruct others on
         | how to setup.
         | 
         | Hotspots often support NEMA GPS protocol to use them as a GPS
         | receiver. All those devices could be powered more efficiently
         | with a DC to DC power supply.
        
         | physhster wrote:
         | I was going to mention that but you beat me to it... The power
         | distribution is not very efficient, but hey, if it's stupid and
         | it works, then it's not stupid.
        
           | monocasa wrote:
           | To be fair, the conversion to AC to go through a transformer
           | on each wart imparts a decent amount of isolation on the
           | voltage supply side.
           | 
           | Does that actually matter? Probably not, but I find the
           | comparison to Docker apropos. Sometimes it's just easier to
           | add/keep abstraction/isolation simply on the small off chance
           | that it's lack does get in your way as long as that
           | abstraction/isloation itself doesn't get too much in your
           | way.
        
           | dylan604 wrote:
           | This is the docker version of hardware prototyping.
        
           | msla wrote:
           | > if it's stupid and it works, then it's not stupid.
           | 
           | I hate this phrase.
           | 
           | Leaded gasoline worked, but it was so stupid it actively made
           | people stupid.
           | 
           | Storing passwords plaintext works, but the first time your
           | system gets broken into it's a massive problem.
           | 
           | Driving at 80 mph in a rainstorm is stupid and it works until
           | it rather spectacularly doesn't.
        
             | giantrobot wrote:
             | The "works" part of the phrase does a lot of heavy lifting.
             | Things can "work" in one dimension/context and fail in
             | others. Stupid things can also "work" in several
             | dimensions/contexts as well as smarter solutions.
        
         | NietTim wrote:
         | Research projects dont need to be "production ready" though
        
           | sitzkrieg wrote:
           | yeah was going to mention this, sounds like prototype is
           | working with COTS parts
        
             | callalex wrote:
             | Cost of tech? sold?
        
               | h2odragon wrote:
               | Commercial Off The Shelf
        
         | giantg2 wrote:
         | If it works, it works
        
       | morpheuskafka wrote:
       | Here's something I've never understood about these: as devices
       | that transmit on FCC-licensed bands, wouldn't each use of these
       | require specific permission from the FCC? Especially for state
       | level law enforcement and state courts, they wouldn't have the
       | authority to authorize this without the federal government saying
       | it's OK.
        
         | diydsp wrote:
         | I dont think they need to xmit beyond the baitphone making
         | standard connections.
         | 
         | Also there are apps for scanning and tracking celltower stength
         | and mass-logging GPS data. I think that data could be the input
         | to their detector... don't need a trunk full of HW.
        
           | ajsnigrutin wrote:
           | Yes, there are (eg. wigle.net, mostly based around wifi, but
           | also scans cell towers), but the data is very noisy, since
           | every phone is different and everyone wears it differently
           | (if you wear it higher, in a shirt pocket, you'll get higher
           | signal levels than if you carry it in a pants pocket, or in
           | your hand, or if you have an old iphone, if you're holding it
           | in your left hand instead of the right).
        
           | diydsp wrote:
           | Would anyone who downvoted this please explain why they think
           | this system needs any special permission from the FCC?
           | Afaict, it's simply monitoring the interactions of its bait
           | phone with towers.
        
             | 14 wrote:
             | Probably downvoting your comment about not needing a trunk
             | full of hardware.
             | 
             | " These sensors have advantages over phones because they
             | can contain specialized cellular scanning equipment and
             | external antennas for farther reception ranges. While phone
             | apps can see limited information on the tower currently
             | connected to, our sensors scan the spectrum to measure
             | hundreds of channels at a time and dozens of broadcast
             | properties."
             | 
             | So there is an advantage over using a regular cell phone
             | and an app.
        
             | callalex wrote:
             | The discussion is about FCC approval for the police to set
             | up a rogue cell site, not FCC approval for this research
             | project.
        
         | upofadown wrote:
         | Last I looked at this the FCC had issued an exception to the
         | normal rules against intentional interference. The resulting
         | license is based on the idea that the devices will only be used
         | under emergency conditions. Presumably the operators of the
         | devices are having lots of emergencies.
         | 
         | I think the problem here is that the federal law against
         | intentional interference is quite definite. So this is the best
         | loophole that the FCC could come up with.
        
         | ceejayoz wrote:
         | https://www.eff.org/deeplinks/2016/08/fcc-created-stingray-p...
         | 
         | > The FCC's involvement in cell site simulators began years ago
         | when it first approved commercial sales to law enforcement.
         | Documents disclosed under FOIA show that the company that sells
         | Stingrays had local police departments lobby the FCC close to
         | ten years ago for approval.
        
         | vngzs wrote:
         | That's a question shared by several US senators [0]. Ron Wyden
         | sent a similar letter in 2018, which received a response from
         | an assistant attorney general, not the FCC [1].
         | 
         | [0]:
         | https://www.eff.org/files/2016/10/06/senate_letter_to_fcc_on...
         | 
         | [1]: https://docs.fcc.gov/public/attachments/DOC-355228A2.pdf
        
       | avg_dev wrote:
       | beautiful image at the top of the page. I realize that it is a
       | map, meant to convey some information. but I just like it
        
       | ncr100 wrote:
       | If I read the results correctly, weird to see a potential cell-
       | catcher at the US Immigration center. Could this reasonably be
       | interpreted as "someone is sniffing immigrant's cell traffic" ..
       | gathering intelligence about potential candidates for
       | immigration?
        
         | ajsnigrutin wrote:
         | During the "migrant waves" a few years ago (2015+, when angela
         | merkel invited them, then left most of them "outside"), our
         | telcos actually gave out free sim cards with a few gigs of data
         | traffic as a "gift" to migrants, and there was a lot of
         | complaining since noone figured out that those can be used for
         | tracking those people, both in my country and also other EU
         | countries, wherever they went legally or not.
        
         | techdmn wrote:
         | Just a wild guess, but If I were trying to find illegal
         | immigrants, seeding a social graph with legal immigrants might
         | be a good place to start. (This comment is in no way an
         | endorsement of the methods or goals of ICE.)
        
           | willcipriano wrote:
           | They straight up give them cell phones when they release them
           | into the interior[0]. None of that is required.
           | 
           | This is to catch mules bringing over drugs and sex
           | traffickers most likely. Once they get to the other side,
           | need to call for a pick up.
           | 
           | [0]https://apnews.com/article/immigration-covid-technology-
           | busi...
        
       | Havoc wrote:
       | Pretty sure it's possible to catch some imsi 100% passive though
       | during handover
        
       | guwop wrote:
       | this is from 17' does anyone know of any updated resources on
       | imsi detection? perhaps some cool papers?
        
         | notjulianjaynes wrote:
         | This is no longer being maintained as of 2022, but I think is
         | more recent than SeaGlass.
         | 
         | https://github.com/EFForg/crocodilehunter
        
       | wintermutestwin wrote:
       | I always figure that the times when I have 3 bars and yet zero
       | internet are when local leo is using a stingray. You would think
       | cell providers would sue over the disruption of their service.
       | 
       | /i am mostly clue free about this stuff so this post might
       | include erroneous assumptions
        
         | [deleted]
        
       | [deleted]
        
       | abraae wrote:
       | > There are some cases where legitimate cell towers will be moved
       | to deal with a temporary increase in demand, like a sporting
       | event, but this is relatively uncommon.
       | 
       | My understanding is these are quite commonly used for concerts,
       | sporting events etc., Vodafone called them COWS (Cell site on
       | wheels).
       | 
       | Anecdotally when the Vodafone CEO of the time came to visit NZ,
       | some lackeys were charged with staying physically close behind
       | him with a COW so he would always see good reception.
        
         | [deleted]
        
       | dang wrote:
       | Related:
       | 
       |  _SeaGlass: City-Wide IMSI-Catcher Detection (2017)_ -
       | https://news.ycombinator.com/item?id=27173717 - May 2021 (55
       | comments)
       | 
       |  _SeaGlass - Enabling City-Wide IMSI-Catcher Detection_ -
       | https://news.ycombinator.com/item?id=14474956 - June 2017 (36
       | comments)
        
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       (page generated 2023-08-23 23:00 UTC)