Tag Archives: tracking

Tracking People by their MAC Addresses

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/09/tracking-people-by-their-mac-addresses.html

Yet another article on the privacy risks of static MAC addresses and always-on Bluetooth connections. This one is about wireless headphones.

The good news is that product vendors are fixing this:

Several of the headphones which could be tracked over time are for sale in electronics stores, but according to two of the manufacturers NRK have spoken to, these models are being phased out.

“The products in your line-up, Elite Active 65t, Elite 65e and Evolve 75e, will be going out of production before long and newer versions have already been launched with randomized MAC addresses. We have a lot of focus on privacy by design and we continuously work with the available security measures on the market,” head of PR at Jabra, Claus Fonnesbech says.

“To run Bluetooth Classic we, and all other vendors, are required to have static addresses and you will find that in older products,” Fonnesbech says.

Jens Bjørnkjær Gamborg, head of communications at Bang & Olufsen, says that “this is products that were launched several years ago.”

“All products launched after 2019 randomize their MAC-addresses on a frequent basis as it has become the market standard to do so,” Gamborg says.

EDITED TO ADD (9/13): It’s not enough to randomly change MAC addresses. Any other plaintext identifiers need to be changed at the same time.

Surveillance of the Internet Backbone

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/08/surveillance-of-the-internet-backbone.html

Vice has an article about how data brokers sell access to the Internet backbone. This is netflow data. It’s useful for cybersecurity forensics, but can also be used for things like tracing VPN activity.

At a high level, netflow data creates a picture of traffic flow and volume across a network. It can show which server communicated with another, information that may ordinarily only be available to the server owner or the ISP carrying the traffic. Crucially, this data can be used for, among other things, tracking traffic through virtual private networks, which are used to mask where someone is connecting to a server from, and by extension, their approximate physical location.

In the hands of some governments, that could be dangerous.

Browser Tracking Using Favicons

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/02/browser-tracking-using-favicons.html

Interesting research on persistent web tracking using favicons. (For those who don’t know, favicons are those tiny icons that appear in browser tabs next to the page name.)

Abstract: The privacy threats of online tracking have garnered considerable attention in recent years from researchers and practitioners alike. This has resulted in users becoming more privacy-cautious and browser vendors gradually adopting countermeasures to mitigate certain forms of cookie-based and cookie-less tracking. Nonetheless, the complexity and feature-rich nature of modern browsers often lead to the deployment of seemingly innocuous functionality that can be readily abused by adversaries. In this paper we introduce a novel tracking mechanism that misuses a simple yet ubiquitous browser feature: favicons. In more detail, a website can track users across browsing sessions by storing a tracking identifier as a set of entries in the browser’s dedicated favicon cache, where each entry corresponds to a specific subdomain. In subsequent user visits the website can reconstruct the identifier by observing which favicons are requested by the browser while the user is automatically and rapidly redirected through a series of subdomains. More importantly, the caching of favicons in modern browsers exhibits several unique characteristics that render this tracking vector particularly powerful, as it is persistent (not affected by users clearing their browser data), non-destructive (reconstructing the identifier in subsequent visits does not alter the existing combination of cached entries), and even crosses the isolation of the incognito mode. We experimentally evaluate several aspects of our attack, and present a series of optimization techniques that render our attack practical. We find that combining our favicon-based tracking technique with immutable browser-fingerprinting attributes that do not change over time allows a website to reconstruct a 32-bit tracking identifier in 2 seconds. Furthermore,our attack works in all major browsers that use a favicon cache, including Chrome and Safari. Due to the severity of our attack we propose changes to browsers’ favicon caching behavior that can prevent this form of tracking, and have disclosed our findings to browser vendors who are currently exploring appropriate mitigation strategies.

Another researcher has implemented this proof of concept:

Strehle has set up a website that demonstrates how easy it is to track a user online using a favicon. He said it’s for research purposes, has released his source code online, and detailed a lengthy explanation of how supercookies work on his website.

The scariest part of the favicon vulnerability is how easily it bypasses traditional methods people use to keep themselves private online. According to Strehle, the supercookie bypasses the “private” mode of Chrome, Safari, Edge, and Firefox. Clearing your cache, surfing behind a VPN, or using an ad-blocker won’t stop a malicious favicon from tracking you.

IMSI-Catchers from Canada

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/10/imsi-catchers-from-canada.html

Gizmodo is reporting that Harris Corp. is no longer selling Stingray IMSI-catchers (and, presumably, its follow-on models Hailstorm and Crossbow) to local governments:

L3Harris Technologies, formerly known as the Harris Corporation, notified police agencies last year that it planned to discontinue sales of its surveillance boxes at the local level, according to government records. Additionally, the company would no longer offer access to software upgrades or replacement parts, effectively slapping an expiration date on boxes currently in use. Any advancements in cellular technology, such as the rollout of 5G networks in most major U.S. cities, would render them obsolete.

The article goes on to talk about replacement surveillance systems from the Canadian company Octasic.

Octasic’s Nyxcell V800 can target most modern phones while maintaining the ability to capture older GSM devices. Florida’s state police agency described the device, made for in-vehicle use, as capable of targeting eight frequency bands including GSM (2G), CDMA2000 (3G), and LTE (4G).

[…]

A 2018 patent assigned to Octasic claims that Nyxcell forces a connection with nearby mobile devices when its signal is stronger than the nearest legitimate cellular tower. Once connected, Nyxcell prompts devices to divulge information about its signal strength relative to nearby cell towers. These reported signal strengths (intra-frequency measurement reports) are then used to triangulate the position of a phone.

Octasic appears to lean heavily on the work of Indian engineers and scientists overseas. A self-published biography of the company notes that while the company is headquartered in Montreal, it has “R&D facilities in India,” as well as a “worldwide sales support network.” Nyxcell’s website, which is only a single page requesting contact information, does not mention Octasic by name. Gizmodo was, however, able to recover domain records identifying Octasic as the owner.

The NSA on the Risks of Exposing Location Data

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/08/the_nsa_on_the_.html

The NSA has issued an advisory on the risks of location data.

Mitigations reduce, but do not eliminate, location tracking risks in mobile devices. Most users rely on features disabled by such mitigations, making such safeguards impractical. Users should be aware of these risks and take action based on their specific situation and risk tolerance. When location exposure could be detrimental to a mission, users should prioritize mission risk and apply location tracking mitigations to the greatest extent possible. While the guidance in this document may be useful to a wide range of users, it is intended primarily for NSS/DoD system users.

The document provides a list of mitigation strategies, including turning things off:

If it is critical that location is not revealed for a particular mission, consider the following recommendations:

  • Determine a non-sensitive location where devices with wireless capabilities can be secured prior to the start of any activities. Ensure that the mission site cannot be predicted from this location.
  • Leave all devices with any wireless capabilities (including personal devices) at this non-sensitive location. Turning off the device may not be sufficient if a device has been compromised.
  • For mission transportation, use vehicles without built-in wireless communication capabilities, or turn off the capabilities, if possible.

Of course, turning off your wireless devices is itself a signal that something is going on. It’s hard to be clandestine in our always connected world.

News articles.

Global Surveillance in the Wake of COVID-19

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/04/global_surveill.html

OneZero is tracking thirty countries around the world who are implementing surveillance programs in the wake of COVID-19:

The most common form of surveillance implemented to battle the pandemic is the use of smartphone location data, which can track population-level movement down to enforcing individual quarantines. Some governments are making apps that offer coronavirus health information, while also sharing location information with authorities for a period of time. For instance, in early March, the Iranian government released an app that it pitched as a self-diagnostic tool. While the tool’s efficacy was likely low, given reports of asymptomatic carriers of the virus, the app saved location data of millions of Iranians, according to a Vice report.

One of the most alarming measures being implemented is in Argentina, where those who are caught breaking quarantine are being forced to download an app that tracks their location. In Hong Kong, those arriving in the airport are given electronic tracking bracelets that must be synced to their home location through their smartphone’s GPS signal.

Contact Tracing COVID-19 Infections via Smartphone Apps

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/04/contact_tracing.html

Google and Apple have announced a joint project to create a privacy-preserving COVID-19 contact tracing app. (Details, such as we have them, are here.) It’s similar to the app being developed at MIT, and similar to others being described and developed elsewhere. It’s nice seeing the privacy protections; they’re well thought out.

I was going to write a long essay about the security and privacy concerns, but Ross Anderson beat me to it. (Note that some of his comments are UK-specific.)

First, it isn’t anonymous. Covid-19 is a notifiable disease so a doctor who diagnoses you must inform the public health authorities, and if they have the bandwidth they call you and ask who you’ve been in contact with. They then call your contacts in turn. It’s not about consent or anonymity, so much as being persuasive and having a good bedside manner.

I’m relaxed about doing all this under emergency public-health powers, since this will make it harder for intrusive systems to persist after the pandemic than if they have some privacy theater that can be used to argue that the whizzy new medi-panopticon is legal enough to be kept running.

Second, contact tracers have access to all sorts of other data such as public transport ticketing and credit-card records. This is how a contact tracer in Singapore is able to phone you and tell you that the taxi driver who took you yesterday from Orchard Road to Raffles has reported sick, so please put on a mask right now and go straight home. This must be controlled; Taiwan lets public-health staff access such material in emergencies only.

Third, you can’t wait for diagnoses. In the UK, you only get a test if you’re a VIP or if you get admitted to hospital. Even so the results take 1-3 days to come back. While the VIPs share their status on twitter or facebook, the other diagnosed patients are often too sick to operate their phones.

Fourth, the public health authorities need geographical data for purposes other than contact tracing – such as to tell the army where to build more field hospitals, and to plan shipments of scarce personal protective equipment. There are already apps that do symptom tracking but more would be better. So the UK app will ask for the first three characters of your postcode, which is about enough to locate which hospital you’d end up in.

Fifth, although the cryptographers – and now Google and Apple – are discussing more anonymous variants of the Singapore app, that’s not the problem. Anyone who’s worked on abuse will instantly realise that a voluntary app operated by anonymous actors is wide open to trolling. The performance art people will tie a phone to a dog and let it run around the park; the Russians will use the app to run service-denial attacks and spread panic; and little Johnny will self-report symptoms to get the whole school sent home.

I recommend reading his essay in full. Also worth reading are this EFF essay, and this ACLU white paper.

To me, the real problems aren’t around privacy and security. The efficacy of any app-based contact tracing is still unproven. A “contact” from the point of view of an app isn’t the same as an epidemiological contact. And the ratio of infections to contacts is high. We would have to deal with the false positives (being close to someone else, but separated by a partition or other barrier) and the false negatives (not being close to someone else, but contracting the disease through a mutually touched object). And without cheap, fast, and accurate testing, the information from any of these apps isn’t very useful. So I agree with Ross that this is primarily an exercise in that false syllogism: Something must be done. This is something. Therefore, we must do it. It’s techies proposing tech solutions to what is primarily a social problem.

EDITED TO ADD: Susan Landau on contact tracing apps and how they’re being oversold. And Farzad Mostashari, former coordinator for health IT at the Department of Health and Human Services, on contact tracing apps.

As long as 1) every contact does not result in an infection, and 2) a large percentage of people with the disease are asymptomatic and don’t realize they have it, I can’t see how this sort of app is valuable. If we had cheap, fast, and accurate testing for everyone on demand…maybe. But I still don’t think so.

EDITED TO ADD (4/15): More details from Apple and Google.

Privacy vs. Surveillance in the Age of COVID-19

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/03/privacy_vs_surv.html

The trade-offs are changing:

As countries around the world race to contain the pandemic, many are deploying digital surveillance tools as a means to exert social control, even turning security agency technologies on their own civilians. Health and law enforcement authorities are understandably eager to employ every tool at their disposal to try to hinder the virus ­ even as the surveillance efforts threaten to alter the precarious balance between public safety and personal privacy on a global scale.

Yet ratcheting up surveillance to combat the pandemic now could permanently open the doors to more invasive forms of snooping later.

I think the effects of COVID-19 will be more drastic than the effects of the terrorist attacks of 9/11: not only with respect to surveillance, but across many aspects of our society. And while many things that would never be acceptable during normal time are reasonable things to do right now, we need to makes sure we can ratchet them back once the current pandemic is over.

Cindy Cohn at EFF wrote:

We know that this virus requires us to take steps that would be unthinkable in normal times. Staying inside, limiting public gatherings, and cooperating with medically needed attempts to track the virus are, when approached properly, reasonable and responsible things to do. But we must be as vigilant as we are thoughtful. We must be sure that measures taken in the name of responding to COVID-19 are, in the language of international human rights law, “necessary and proportionate” to the needs of society in fighting the virus. Above all, we must make sure that these measures end and that the data collected for these purposes is not re-purposed for either governmental or commercial ends.

I worry that in our haste and fear, we will fail to do any of that.

More from EFF.

Build a Raspberry Pi Zero W Amazon price tracker

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/build-a-raspberry-pi-zero-w-amazon-price-tracker/

Have you ever missed out on a great deal on Amazon because you were completely unaware it existed? Are you interested in a specific item but waiting for it to go on sale? Here’s help: Devscover’s latest video shows you how to create an Amazon price tracker using Raspberry Pi Zero W and Python.

Build An Amazon Price Tracker With Python

Wayne from Devscover shows you how to code a Amazon Price Tracker with Python! Get started with your first Python project. Land a job at a big firm like Google, Facebook, Twitter or even the less well known but equally exciting big retail organisations or Government with Devscover tutorials and tips.

By following their video tutorial, you can set up a notification system on Raspberry Pi Zero W that emails you every time your chosen item’s price drops. Very nice.

Devscover’s tutorial is so detailed that it seems a waste to try and summarise it here. So instead, why not make yourself a cup of tea and sit down with the video? It’s worth the time investment: if you follow the instructions, you’ll end up with a great piece of tech that’ll save you money!

Remember, if you like what you see, subscribe to the Devscover YouTube channel and give them a thumbs-up for making wonderful Raspberry Pi content!

The post Build a Raspberry Pi Zero W Amazon price tracker appeared first on Raspberry Pi.

Apple’s Tracking-Prevention Feature in Safari has a Privacy Bug

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/02/apples_tracking.html

Last month, engineers at Google published a very curious privacy bug in Apple’s Safari web browser. Apple’s Intelligent Tracking Prevention, a feature designed to reduce user tracking, has vulnerabilities that themselves allow user tracking. Some details:

ITP detects and blocks tracking on the web. When you visit a few websites that happen to load the same third-party resource, ITP detects the domain hosting the resource as a potential tracker and from then on sanitizes web requests to that domain to limit tracking. Tracker domains are added to Safari’s internal, on-device ITP list. When future third-party requests are made to a domain on the ITP list, Safari will modify them to remove some information it believes may allow tracking the user (such as cookies).

[…]

The details should come as a surprise to everyone because it turns out that ITP could effectively be used for:

  • information leaks: detecting websites visited by the user (web browsing history hijacking, stealing a list of visited sites)
  • tracking the user with ITP, making the mechanism function like a cookie
  • fingerprinting the user: in ways similar to the HSTS fingerprint, but perhaps a bit better

I am sure we all agree that we would not expect a privacy feature meant to protect from tracking to effectively enable tracking, and also accidentally allowing any website out there to steal its visitors’ web browsing history. But web architecture is complex, and the consequence is that this is exactly the case.

Apple fixed this vulnerability in December, a month before Google published.

If there’s any lesson here, it’s that privacy is hard — and that privacy engineering is even harder. It’s not that we shouldn’t try, but we should recognize that it’s easy to get it wrong.

Customer Tracking at Ralphs Grocery Store

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/01/customer_tracki.html

To comply with California’s new data privacy law, companies that collect information on consumers and users are forced to be more transparent about it. Sometimes the results are creepy. Here’s an article about Ralphs, a California supermarket chain owned by Kroger:

…the form proceeds to state that, as part of signing up for a rewards card, Ralphs “may collect” information such as “your level of education, type of employment, information about your health and information about insurance coverage you might carry.”

It says Ralphs may pry into “financial and payment information like your bank account, credit and debit card numbers, and your credit history.”

Wait, it gets even better.

Ralphs says it’s gathering “behavioral information” such as “your purchase and transaction histories” and “geolocation data,” which could mean the specific Ralphs aisles you browse or could mean the places you go when not shopping for groceries, thanks to the tracking capability of your smartphone.

Ralphs also reserves the right to go after “information about what you do online” and says it will make “inferences” about your interests “based on analysis of other information we have collected.”

Other information? This can include files from “consumer research firms” ­– read: professional data brokers ­– and “public databases,” such as property records and bankruptcy filings.

The reaction from John Votava, a Ralphs spokesman:

“I can understand why it raises eyebrows,” he said. We may need to change the wording on the form.”

That’s the company’s solution. Don’t spy on people less, just change the wording so they don’t realize it.

More consumer protection laws will be required.

Google Receives Geofence Warrants

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/01/google_receives.html

Sometimes it’s hard to tell the corporate surveillance operations from the government ones:

Google reportedly has a database called Sensorvault in which it stores location data for millions of devices going back almost a decade.

The article is about geofence warrants, where the police go to companies like Google and ask for information about every device in a particular geographic area at a particular time. In 2013, we learned from Edward Snowden that the NSA does this worldwide. Its program is called CO-TRAVELLER. The NSA claims it stopped doing that in 2014 — probably just stopped doing it in the US — but why should it bother when the government can just get the data from Google.

Both the New York Times and EFF have written about Sensorvault.

Wi-Fi Hotspot Tracking

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/10/wi-fi_hotspot_t.html

Free Wi-Fi hotspots can track your location, even if you don’t connect to them. This is because your phone or computer broadcasts a unique MAC address.

What distinguishes location-based marketing hotspot providers like Zenreach and Euclid is that the personal information you enter in the captive portal­ — like your email address, phone number, or social media profile­ — can be linked to your laptop or smartphone’s Media Access Control (MAC) address. That’s the unique alphanumeric ID that devices broadcast when Wi-Fi is switched on.

As Euclid explains in its privacy policy, “…if you bring your mobile device to your favorite clothing store today that is a Location — ­and then a popular local restaurant a few days later that is also a Location­ — we may know that a mobile device was in both locations based on seeing the same MAC Address.”

MAC addresses alone don’t contain identifying information besides the make of a device, such as whether a smartphone is an iPhone or a Samsung Galaxy. But as long as a device’s MAC address is linked to someone’s profile, and the device’s Wi-Fi is turned on, the movements of its owner can be followed by any hotspot from the same provider.

“After a user signs up, we associate their email address and other personal information with their device’s MAC address and with any location history we may previously have gathered (or later gather) for that device’s MAC address,” according to Zenreach’s privacy policy.

The defense is to turn Wi-Fi off on your phone when you’re not using it.

EDITED TO ADD: Note that the article is from 2018. Not that I think anything is different today….

Russians Hack FBI Comms System

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/09/russians_hack_f.html

Yahoo News reported that the Russians have successfully targeted an FBI communications system:

American officials discovered that the Russians had dramatically improved their ability to decrypt certain types of secure communications and had successfully tracked devices used by elite FBI surveillance teams. Officials also feared that the Russians may have devised other ways to monitor U.S. intelligence communications, including hacking into computers not connected to the internet. Senior FBI and CIA officials briefed congressional leaders on these issues as part of a wide-ranging examination on Capitol Hill of U.S. counterintelligence vulnerabilities.

These compromises, the full gravity of which became clear to U.S. officials in 2012, gave Russian spies in American cities including Washington, New York and San Francisco key insights into the location of undercover FBI surveillance teams, and likely the actual substance of FBI communications, according to former officials. They provided the Russians opportunities to potentially shake off FBI surveillance and communicate with sensitive human sources, check on remote recording devices and even gather intelligence on their FBI pursuers, the former officials said.

It’s unclear whether the Russians were able to recover encrypted data or just perform traffic analysis. The Yahoo story implies the former; the NBC News story says otherwise. It’s hard to tell if the reporters truly understand the difference. We do know, from research Matt Blaze and others did almost ten years ago, that at least one FBI radio system was horribly insecure in practice — but not in a way that breaks the encryption. Its poor design just encourages users to turn off the encryption.