Digital Car Keys Are Coming
Soon we will be able to unlock and start our cars from our phones. Let’s hope people are thinking about security.
Entries Tagged "smartphones"
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Using Machine Learning to Detect Keystrokes
Researchers have trained a ML model to detect keystrokes by sound with 95% accuracy.
“A Practical Deep Learning-Based Acoustic Side Channel Attack on Keyboards”
Abstract: With recent developments in deep learning, the ubiquity of microphones and the rise in online services via personal devices, acoustic side channel attacks present a greater threat to keyboards than ever. This paper presents a practical implementation of a state-of-the-art deep learning model in order to classify laptop keystrokes, using a smartphone integrated microphone. When trained on keystrokes recorded by a nearby phone, the classifier achieved an accuracy of 95%, the highest accuracy seen without the use of a language model. When trained on keystrokes recorded using the video-conferencing software Zoom, an accuracy of 93% was achieved, a new best for the medium. Our results prove the practicality of these side channel attacks via off-the-shelf equipment and algorithms. We discuss a series of mitigation methods to protect users against these series of attacks.
News article.
Brute-Forcing a Fingerprint Reader
It’s neither hard nor expensive:
Unlike password authentication, which requires a direct match between what is inputted and what’s stored in a database, fingerprint authentication determines a match using a reference threshold. As a result, a successful fingerprint brute-force attack requires only that an inputted image provides an acceptable approximation of an image in the fingerprint database. BrutePrint manipulates the false acceptance rate (FAR) to increase the threshold so fewer approximate images are accepted.
BrutePrint acts as an adversary in the middle between the fingerprint sensor and the trusted execution environment and exploits vulnerabilities that allow for unlimited guesses.
In a BrutePrint attack, the adversary removes the back cover of the device and attaches the $15 circuit board that has the fingerprint database loaded in the flash storage. The adversary then must convert the database into a fingerprint dictionary that’s formatted to work with the specific sensor used by the targeted phone. The process uses a neural-style transfer when converting the database into the usable dictionary. This process increases the chances of a match.
With the fingerprint dictionary in place, the adversary device is now in a position to input each entry into the targeted phone. Normally, a protection known as attempt limiting effectively locks a phone after a set number of failed login attempts are reached. BrutePrint can fully bypass this limit in the eight tested Android models, meaning the adversary device can try an infinite number of guesses. (On the two iPhones, the attack can expand the number of guesses to 15, three times higher than the five permitted.)
The bypasses result from exploiting what the researchers said are two zero-day vulnerabilities in the smartphone fingerprint authentication framework of virtually all smartphones. The vulnerabilities—one known as CAMF (cancel-after-match fail) and the other MAL (match-after-lock)—result from logic bugs in the authentication framework. CAMF exploits invalidate the checksum of transmitted fingerprint data, and MAL exploits infer matching results through side-channel attacks.
Depending on the model, the attack takes between 40 minutes and 14 hours.
Also:
The ability of BrutePrint to successfully hijack fingerprints stored on Android devices but not iPhones is the result of one simple design difference: iOS encrypts the data, and Android does not.
FBI Advising People to Avoid Public Charging Stations
The FBI is warning people against using public phone-charging stations, worrying that the combination power-data port can be used to inject malware onto the devices:
Avoid using free charging stations in airports, hotels, or shopping centers. Bad actors have figured out ways to use public USB ports to introduce malware and monitoring software onto devices that access these ports. Carry your own charger and USB cord and use an electrical outlet instead.
How much of a risk is this, really? I am unconvinced, although I do carry a USB condom for charging stations I find suspicious.
News article.
Hacked Cellebrite and MSAB Software Released
Cellebrite is an cyberweapons arms manufacturer that sells smartphone forensic software to governments around the world. MSAB is a Swedish company that does the same thing. Someone has released software and documentation from both companies.
Recovering Smartphone Voice from the Accelerometer
Yet another smartphone side-channel attack: “EarSpy: Spying Caller Speech and Identity through Tiny Vibrations of Smartphone Ear Speakers“:
Abstract: Eavesdropping from the user’s smartphone is a well-known threat to the user’s safety and privacy. Existing studies show that loudspeaker reverberation can inject speech into motion sensor readings, leading to speech eavesdropping. While more devastating attacks on ear speakers, which produce much smaller scale vibrations, were believed impossible to eavesdrop with zero-permission motion sensors. In this work, we revisit this important line of reach. We explore recent trends in smartphone manufacturers that include extra/powerful speakers in place of small ear speakers, and demonstrate the feasibility of using motion sensors to capture such tiny speech vibrations. We investigate the impacts of these new ear speakers on built-in motion sensors and examine the potential to elicit private speech information from the minute vibrations. Our designed system EarSpy can successfully detect word regions, time, and frequency domain features and generate a spectrogram for each word region. We train and test the extracted data using classical machine learning algorithms and convolutional neural networks. We found up to 98.66% accuracy in gender detection, 92.6% detection in speaker detection, and 56.42% detection in digit detection (which is 5X more significant than the random selection (10%)). Our result unveils the potential threat of eavesdropping on phone conversations from ear speakers using motion sensors.
It’s not great, but it’s an impressive start.
Ukraine Intercepting Russian Soldiers’ Cell Phone Calls
They’re using commercial phones, which go through the Ukrainian telecom network:
“You still have a lot of soldiers bringing cellphones to the frontline who want to talk to their families and they are either being intercepted as they go through a Ukrainian telecommunications provider or intercepted over the air,” said Alperovitch. “That doesn’t pose too much difficulty for the Ukrainian security services.”
[…]
“Security has always been a mess, both in the army and among defence officials,” the source said. “For example, in 2013 they tried to get all the staff at the ministry of defence to replace our iPhones with Russian-made Yoto smartphones.
“But everyone just kept using the iPhone as a second mobile because it was much better. We would just keep the iPhone in the car’s glove compartment for when we got back from work. In the end, the ministry gave up and stopped caring. If the top doesn’t take security very seriously, how can you expect any discipline in the regular army?”
This isn’t a new problem and it isn’t a Russian problem. Here’s a more general article on the problem from 2020.
Russian Software Company Pretending to Be American
Computer code developed by a company called Pushwoosh is in about 8,000 Apple and Google smartphone apps. The company pretends to be American when it is actually Russian.
According to company documents publicly filed in Russia and reviewed by Reuters, Pushwoosh is headquartered in the Siberian town of Novosibirsk, where it is registered as a software company that also carries out data processing. It employs around 40 people and reported revenue of 143,270,000 rubles ($2.4 mln) last year. Pushwoosh is registered with the Russian government to pay taxes in Russia.
On social media and in US regulatory filings, however, it presents itself as a US company, based at various times in California, Maryland, and Washington, DC, Reuters found.
What does the code do? Spy on people:
Pushwoosh provides code and data processing support for software developers, enabling them to profile the online activity of smartphone app users and send tailor-made push notifications from Pushwoosh servers.
On its website, Pushwoosh says it does not collect sensitive information, and Reuters found no evidence Pushwoosh mishandled user data. Russian authorities, however, have compelled local companies to hand over user data to domestic security agencies.
I have called supply chain security “an insurmountably hard problem,” and this is just another example of that.
EDITED TO ADD (12/12): Here is a list of apps that use the Pushwoosh SDK.
Another Event-Related Spyware App
Last month, we were warned not to install Qatar’s World Cup app because it was spyware. This month, it’s Egypt’s COP27 Summit app:
The app is being promoted as a tool to help attendees navigate the event. But it risks giving the Egyptian government permission to read users’ emails and messages. Even messages shared via encrypted services like WhatsApp are vulnerable, according to POLITICO’s technical review of the application, and two of the outside experts.
The app also provides Egypt’s Ministry of Communications and Information Technology, which created it, with other so-called backdoor privileges, or the ability to scan people’s devices.
On smartphones running Google’s Android software, it has permission to potentially listen into users’ conversations via the app, even when the device is in sleep mode, according to the three experts and POLITICO’s separate analysis. It can also track people’s locations via smartphone’s built-in GPS and Wi-Fi technologies, according to two of the analysts.
Credit Card Fraud That Bypasses 2FA
Someone in the UK is stealing smartphones and credit cards from people who have stored them in gym lockers, and is using the two items in combination to commit fraud:
Phones, of course, can be made inaccessible with the use of passwords and face or fingerprint unlocking. And bank cards can be stopped.
But the thief has a method which circumnavigates those basic safety protocols.
Once they have the phone and the card, they register the card on the relevant bank’s app on their own phone or computer. Since it is the first time that card will have been used on the new device, a one-off security passcode is demanded.
That verification passcode is sent by the bank to the stolen phone. The code flashes up on the locked screen of the stolen phone, leaving the thief to tap it into their own device. Once accepted, they have control of the bank account. They can transfer money or buy goods, or change access to the account.
Sidebar photo of Bruce Schneier by Joe MacInnis.