Entries Tagged "smartphones"

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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.

Posted on December 30, 2022 at 7:18 AMView Comments

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.

Posted on December 21, 2022 at 7:09 AMView Comments

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.

Posted on November 16, 2022 at 6:03 AMView Comments

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.

Posted on November 15, 2022 at 7:16 AMView Comments

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.

Posted on September 20, 2022 at 6:29 AMView Comments

Smartphones and Civilians in Wartime

Interesting article about civilians using smartphones to assist their militaries in wartime, and how that blurs the important legal distinction between combatants and non-combatants:

The principle of distinction between the two roles is a critical cornerstone of international humanitarian law­—the law of armed conflict, codified by decades of customs and laws such as the Geneva Conventions. Those considered civilians and civilian targets are not to be attacked by military forces; as they are not combatants, they should be spared. At the same time, they also should not act as combatants—­if they do, they may lose this status.

The conundrum, then, is how to classify a civilian who, with the use of their smartphone, potentially becomes an active participant in a military sensor system. (To be clear, solely having the app installed is not sufficient to lose the protected status. What matters is actual usage.) The Additional Protocol I to Geneva Conventions states that civilians enjoy protection from the “dangers arising from military operations unless and for such time as they take a direct part in hostilities.” Legally, if civilians engage in military activity, such as taking part in hostilities by using weapons, they forfeit their protected status, “for such time as they take a direct part in hostilities” that “affect[s] the military operations,” according to the International Committee of the Red Cross, the traditional impartial custodian of International Humanitarian Law. This is the case even if the people in question are not formally members of the armed forces. By losing the status of a civilian, one may become a legitimate military objective, carrying the risk of being directly attacked by military forces.

Posted on June 9, 2022 at 6:22 AMView Comments

Using Pupil Reflection in Smartphone Camera Selfies

Researchers are using the reflection of the smartphone in the pupils of faces taken as selfies to infer information about how the phone is being used:

For now, the research is focusing on six different ways a user can hold a device like a smartphone: with both hands, just the left, or just the right in portrait mode, and the same options in horizontal mode.

It’s not a lot of information, but it’s a start. (It’ll be a while before we can reproduce these results from Blade Runner.)

Research paper.

Posted on May 3, 2022 at 11:17 AMView Comments

Samsung Encryption Flaw

Researchers have found a major encryption flaw in 100 million Samsung Galaxy phones.

From the abstract:

In this work, we expose the cryptographic design and implementation of Android’s Hardware-Backed Keystore in Samsung’s Galaxy S8, S9, S10, S20, and S21 flagship devices. We reversed-engineered and provide a detailed description of the cryptographic design and code structure, and we unveil severe design flaws. We present an IV reuse attack on AES-GCM that allows an attacker to extract hardware-protected key material, and a downgrade attack that makes even the latest Samsung devices vulnerable to the IV reuse attack. We demonstrate working key extraction attacks on the latest devices. We also show the implications of our attacks on two higher-level cryptographic protocols between the TrustZone and a remote server: we demonstrate a working FIDO2 WebAuthn login bypass and a compromise of Google’s Secure Key Import.

Here are the details:

As we discussed in Section 3, the wrapping key used to encrypt the key blobs (HDK) is derived using a salt value computed by the Keymaster TA. In v15 and v20-s9 blobs, the salt is a deterministic function that depends only on the application ID and application data (and constant strings), which the Normal World client fully controls. This means that for a given application, all key blobs will be encrypted using the same key. As the blobs are encrypted in AES-GCM mode-of-operation, the security of the resulting encryption scheme depends on its IV values never being reused.

Gadzooks. That’s a really embarrassing mistake. GSM needs a new nonce for every encryption. Samsung took a secure cipher mode and implemented it insecurely.

News article.

Posted on March 4, 2022 at 6:19 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.