Entries Tagged "Android"

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Wallpaper that Crashes Android Phones

This is interesting:

The image, a seemingly innocuous sunset (or dawn) sky above placid waters, may be viewed without harm. But if loaded as wallpaper, the phone will crash.

The fault does not appear to have been maliciously created. Rather, according to developers following Ice Universe’s Twitter thread, the problem lies in the way color space is handled by the Android OS.

The image was created using the RGB color space to display image hues, while Android 10 uses the sRGB color space protocol, according to 9to5Google contributor Dylan Roussel. When the Android phone cannot properly convert the Adobe RGB image, it crashes.

Posted on June 3, 2020 at 6:11 AM • View Comments

Hacking Voice Assistants with Ultrasonic Waves

I previously wrote about hacking voice assistants with lasers. Turns you can do much the same thing with ultrasonic waves:

Voice assistants—the demo targeted Siri, Google Assistant, and Bixby—are designed to respond when they detect the owner’s voice after noticing a trigger phrase such as ‘Ok, Google’.

Ultimately, commands are just sound waves, which other researchers have already shown can be emulated using ultrasonic waves which humans can’t hear, providing an attacker has a line of sight on the device and the distance is short.

What SurfingAttack adds to this is the ability to send the ultrasonic commands through a solid glass or wood table on which the smartphone was sitting using a circular piezoelectric disc connected to its underside.

Although the distance was only 43cm (17 inches), hiding the disc under a surface represents a more plausible, easier-to-conceal attack method than previous techniques.

Research paper. Demonstration video.

Posted on March 23, 2020 at 6:19 AM • View Comments

Voatz Internet Voting App Is Insecure

This paper describes the flaws in the Voatz Internet voting app: “The Ballot is Busted Before the Blockchain: A Security Analysis of Voatz, the First Internet Voting Application Used in U.S. Federal Elections.”

Abstract: In the 2018 midterm elections, West Virginia became the first state in the U.S. to allow select voters to cast their ballot on a mobile phone via a proprietary app called “Voatz.” Although there is no public formal description of Voatz’s security model, the company claims that election security and integrity are maintained through the use of a permissioned blockchain, biometrics, a mixnet, and hardware-backed key storage modules on the user’s device. In this work, we present the first public security analysis of Voatz, based on a reverse engineering of their Android application and the minimal available documentation of the system. We performed a clean-room reimplementation of Voatz’s server and present an analysis of the election process as visible from the app itself.

We find that Voatz has vulnerabilities that allow different kinds of adversaries to alter, stop, or expose a user’s vote,including a sidechannel attack in which a completely passive network adversary can potentially recover a user’s secret ballot. We additionally find that Voatz has a number of privacy issues stemming from their use of third party services for crucial app functionality. Our findings serve as a concrete illustration of the common wisdom against Internet voting,and of the importance of transparency to the legitimacy of elections.

News articles.

The company’s response is a perfect illustration of why non-computer non-security companies have no idea what they’re doing, and should not be trusted with any form of security.

EDITED TO ADD (3/11): The researchers respond to Voatz’s response.

Posted on February 17, 2020 at 6:35 AM • View Comments

Security Vulnerabilities in Android Firmware

Researchers have discovered and revealed 146 vulnerabilities in various incarnations of Android smartphone firmware. The vulnerabilities were found by scanning the phones of 29 different Android makers, and each is unique to a particular phone or maker. They were found using automatic tools, and it is extremely likely that many of the vulnerabilities are not exploitable—making them bugs but not security concerns. There is no indication that any of these vulnerabilities were put there on purpose, although it is reasonable to assume that other organizations do this same sort of scanning and use the findings for attack. And since they’re firmware bugs, in many cases there is no ability to patch them.

I see this as yet another demonstration of how hard supply chain security is.

News article.

Posted on November 18, 2019 at 6:33 AM • View Comments

xHelper Malware for Android

xHelper is not interesting because of its infection mechanism; the user has to side-load an app onto his phone. It’s not interesting because of its payload; it seems to do nothing more than show unwanted ads. it’s interesting because of its persistence:

Furthermore, even if users spot the xHelper service in the Android operating system’s Apps section, removing it doesn’t work, as the trojan reinstalls itself every time, even after users perform a factory reset of the entire device.

How xHelper survives factory resets is still a mystery; however, both Malwarebytes and Symantec said xHelper doesn’t tamper with system services system apps. In addition, Symantec also said that it was “unlikely that Xhelper comes preinstalled on devices.”

In some cases, users said that even when they removed the xHelper service and then disabled the “Install apps from unknown sources” option, the setting kept turning itself back on, and the device was reinfected in a matter of minutes after being cleaned.

From Symantec:

We first began seeing Xhelper apps in March 2019. Back then, the malware’s code was relatively simple, and its main function was visiting advertisement pages for monetization purposes. The code has changed over time. Initially, the malware’s ability to connect to a C&C server was written directly into the malware itself, but later this functionality was moved to an encrypted payload, in an attempt to evade signature detection. Some older variants included empty classes that were not implemented at the time, but the functionality is now fully enabled. As described previously, Xhelper’s functionality has expanded drastically in recent times.

We strongly believe that the malware’s source code is still a work in progress.

It’s a weird piece of malware. That level of persistence speaks to a nation-state actor. The continuous evolution of the malware implies an organized actor. But sending unwanted ads is far too noisy for any serious use. And the infection mechanism is pretty random. I just don’t know.

Posted on November 8, 2019 at 6:10 AM • View Comments

Massive iPhone Hack Targets Uyghurs

China is being blamed for a massive surveillance operation that targeted Uyghur Muslims. This story broke in waves, the first wave being about the iPhone.

Earlier this year, Google’s Project Zero found a series of websites that have been using zero-day vulnerabilities to indiscriminately install malware on iPhones that would visit the site. (The vulnerabilities were patched in iOS 12.1.4, released on February 7.)

Earlier this year Google’s Threat Analysis Group (TAG) discovered a small collection of hacked websites. The hacked sites were being used in indiscriminate watering hole attacks against their visitors, using iPhone 0-day.

There was no target discrimination; simply visiting the hacked site was enough for the exploit server to attack your device, and if it was successful, install a monitoring implant. We estimate that these sites receive thousands of visitors per week.

TAG was able to collect five separate, complete and unique iPhone exploit chains, covering almost every version from iOS 10 through to the latest version of iOS 12. This indicated a group making a sustained effort to hack the users of iPhones in certain communities over a period of at least two years.

Four more news stories.

This upends pretty much everything we know about iPhone hacking. We believed that it was hard. We believed that effective zero-day exploits cost $2M or $3M, and were used sparingly by governments only against high-value targets. We believed that if an exploit was used too frequently, it would be quickly discovered and patched.

None of that is true here. This operation used fourteen zero-days exploits. It used them indiscriminately. And it remained undetected for two years. (I waited before posting this because I wanted to see if someone would rebut this story, or explain it somehow.)

Google’s announcement left out of details, like the URLs of the sites delivering the malware. That omission meant that we had no idea who was behind the attack, although the speculation was that it was a nation-state.

Subsequent reporting added that malware against Android phones and the Windows operating system were also delivered by those websites. And then that the websites were targeted at Uyghurs. Which leads us all to blame China.

So now this is a story of a large, expensive, indiscriminate, Chinese-run surveillance operation against an ethnic minority in their country. And the politics will overshadow the tech. But the tech is still really impressive.

EDITED TO ADD: New data on the value of smartphone exploits:

According to the company, starting today, a zero-click (no user interaction) exploit chain for Android can get hackers and security researchers up to $2.5 million in rewards. A similar exploit chain impacting iOS is worth only $2 million.

EDITED TO ADD (9/6): Apple disputes some of the claims Google made about the extent of the vulnerabilities and the attack.

EDITED TO ADD (9/7): More on Apple’s pushbacks.

Posted on September 3, 2019 at 6:09 AM • View Comments

Backdoor Built into Android Firmware

In 2017, some Android phones came with a backdoor pre-installed:

Criminals in 2017 managed to get an advanced backdoor preinstalled on Android devices before they left the factories of manufacturers, Google researchers confirmed on Thursday.

Triada first came to light in 2016 in articles published by Kaspersky here and here, the first of which said the malware was “one of the most advanced mobile Trojans” the security firm’s analysts had ever encountered. Once installed, Triada’s chief purpose was to install apps that could be used to send spam and display ads. It employed an impressive kit of tools, including rooting exploits that bypassed security protections built into Android and the means to modify the Android OS’ all-powerful Zygote process. That meant the malware could directly tamper with every installed app. Triada also connected to no fewer than 17 command and control servers.

In July 2017, security firm Dr. Web reported that its researchers had found Triada built into the firmware of several Android devices, including the Leagoo M5 Plus, Leagoo M8, Nomu S10, and Nomu S20. The attackers used the backdoor to surreptitiously download and install modules. Because the backdoor was embedded into one of the OS libraries and located in the system section, it couldn’t be deleted using standard methods, the report said.

On Thursday, Google confirmed the Dr. Web report, although it stopped short of naming the manufacturers. Thursday’s report also said the supply chain attack was pulled off by one or more partners the manufacturers used in preparing the final firmware image used in the affected devices.

This is a supply chain attack. It seems to be the work of criminals, but it could just as easily have been a nation-state.

Posted on June 21, 2019 at 11:42 AM • View Comments

Android Ad-Fraud Scheme

BuzzFeed is reporting on a scheme where fraudsters buy legitimate Android apps, track users’ behavior in order to mimic it in a way that evades bot detectors, and then uses bots to perpetuate an ad-fraud scheme.

After being provided with a list of the apps and websites connected to the scheme, Google investigated and found that dozens of the apps used its mobile advertising network. Its independent analysis confirmed the presence of a botnet driving traffic to websites and apps in the scheme. Google has removed more than 30 apps from the Play store, and terminated multiple publisher accounts with its ad networks. Google said that prior to being contacted by BuzzFeed News it had previously removed 10 apps in the scheme and blocked many of the websites. It continues to investigate, and published a blog post to detail its findings.

The company estimates this operation stole close to $10 million from advertisers who used Google’s ad network to place ads in the affected websites and apps. It said the vast majority of ads being placed in these apps and websites came via other major ad networks.

Lots of details in both the BuzzFeed and the Google links.

The Internet advertising industry is rife with fraud, at all levels. This is just one scheme among many.

Posted on October 25, 2018 at 6:49 AM • View Comments

Google Tracks Its Users Even If They Opt Out of Tracking

Google is tracking you, even if you turn off tracking:

Google says that will prevent the company from remembering where you’ve been. Google’s support page on the subject states: “You can turn off Location History at any time. With Location History off, the places you go are no longer stored.”

That isn’t true. Even with Location History paused, some Google apps automatically store time-stamped location data without asking.

For example, Google stores a snapshot of where you are when you merely open its Maps app. Automatic daily weather updates on Android phones pinpoint roughly where you are. And some searches that have nothing to do with location, like “chocolate chip cookies,” or “kids science kits,” pinpoint your precise latitude and longitude ­- accurate to the square foot -­ and save it to your Google account.

On the one hand, this isn’t surprising to technologists. Lots of applications use location data. On the other hand, it’s very surprising—and counterintuitive—to everyone else. And that’s why this is a problem.

I don’t think we should pick on Google too much, though. Google is a symptom of the bigger problem: surveillance capitalism in general. As long as surveillance is the business model of the Internet, things like this are inevitable.

BoingBoing story.

Good commentary.

Posted on August 14, 2018 at 6:22 AM • View Comments

Russian Censorship of Telegram

Internet censors have a new strategy in their bid to block applications and websites: pressuring the large cloud providers that host them. These providers have concerns that are much broader than the targets of censorship efforts, so they have the choice of either standing up to the censors or capitulating in order to maximize their business. Today’s Internet largely reflects the dominance of a handful of companies behind the cloud services, search engines and mobile platforms that underpin the technology landscape. This new centralization radically tips the balance between those who want to censor parts of the Internet and those trying to evade censorship. When the profitable answer is for a software giant to acquiesce to censors’ demands, how long can Internet freedom last?

The recent battle between the Russian government and the Telegram messaging app illustrates one way this might play out. Russia has been trying to block Telegram since April, when a Moscow court banned it after the company refused to give Russian authorities access to user messages. Telegram, which is widely used in Russia, works on both iPhone and Android, and there are Windows and Mac desktop versions available. The app offers optional end-to-end encryption, meaning that all messages are encrypted on the sender’s phone and decrypted on the receiver’s phone; no part of the network can eavesdrop on the messages.

Since then, Telegram has been playing cat-and-mouse with the Russian telecom regulator Roskomnadzor by varying the IP address the app uses to communicate. Because Telegram isn’t a fixed website, it doesn’t need a fixed IP address. Telegram bought tens of thousands of IP addresses and has been quickly rotating through them, staying a step ahead of censors. Cleverly, this tactic is invisible to users. The app never sees the change, or the entire list of IP addresses, and the censor has no clear way to block them all.

A week after the court ban, Roskomnadzor countered with an unprecedented move of its own: blocking 19 million IP addresses, many on Amazon Web Services and Google Cloud. The collateral damage was widespread: The action inadvertently broke many other web services that use those platforms, and Roskomnadzor scaled back after it became clear that its action had affected services critical for Russian business. Even so, the censor is still blocking millions of IP addresses.

More recently, Russia has been pressuring Apple not to offer the Telegram app in its iPhone App Store. As of this writing, Apple has not complied, and the company has allowed Telegram to download a critical software update to iPhone users (after what the app’s founder called a delay last month). Roskomnadzor could further pressure Apple, though, including by threatening to turn off its entire iPhone app business in Russia.

Telegram might seem a weird app for Russia to focus on. Those of us who work in security don’t recommend the program, primarily because of the nature of its cryptographic protocols. In general, proprietary cryptography has numerous fatal security flaws. We generally recommend Signal for secure SMS messaging, or, if having that program on your computer is somehow incriminating, WhatsApp. (More than 1.5 billion people worldwide use WhatsApp.) What Telegram has going for it is that it works really well on lousy networks. That’s why it is so popular in places like Iran and Afghanistan. (Iran is also trying to ban the app.)

What the Russian government doesn’t like about Telegram is its anonymous broadcast feature­—channel capability and chats—­which makes it an effective platform for political debate and citizen journalism. The Russians might not like that Telegram is encrypted, but odds are good that they can simply break the encryption. Telegram’s role in facilitating uncontrolled journalism is the real issue.

Iran attempts to block Telegram have been more successful than Russia’s, less because Iran’s censorship technology is more sophisticated but because Telegram is not willing to go as far to defend Iranian users. The reasons are not rooted in business decisions. Simply put, Telegram is a Russian product and the designers are more motivated to poke Russia in the eye. Pavel Durov, Telegram’s founder, has pledged millions of dollars to help fight Russian censorship.

For the moment, Russia has lost. But this battle is far from over. Russia could easily come back with more targeted pressure on Google, Amazon and Apple. A year earlier, Zello used the same trick Telegram is using to evade Russian censors. Then, Roskomnadzor threatened to block all of Amazon Web Services and Google Cloud; and in that instance, both companies forced Zello to stop its IP-hopping censorship-evasion tactic.

Russia could also further develop its censorship infrastructure. If its capabilities were as finely honed as China’s, it would be able to more effectively block Telegram from operating. Right now, Russia can block only specific IP addresses, which is too coarse a tool for this issue. Telegram’s voice capabilities in Russia are significantly degraded, however, probably because high-capacity IP addresses are easier to block.

Whatever its current frustrations, Russia might well win in the long term. By demonstrating its willingness to suffer the temporary collateral damage of blocking major cloud providers, it prompted cloud providers to block another and more effective anti-censorship tactic, or at least accelerated the process. In April, Google and Amazon banned­—and technically blocked­—the practice of “domain fronting,” a trick anti-censorship tools use to get around Internet censors by pretending to be other kinds of traffic. Developers would use popular websites as a proxy, routing traffic to their own servers through another website­—in this case Google.com­—to fool censors into believing the traffic was intended for Google.com. The anonymous web-browsing tool Tor has used domain fronting since 2014. Signal, since 2016. Eliminating the capability is a boon to censors worldwide.

Tech giants have gotten embroiled in censorship battles for years. Sometimes they fight and sometimes they fold, but until now there have always been options. What this particular fight highlights is that Internet freedom is increasingly in the hands of the world’s largest Internet companies. And while freedom may have its advocates—­the American Civil Liberties Union has tweeted its support for those companies, and some 12,000 people in Moscow protested against the Telegram ban­—actions such as disallowing domain fronting illustrate that getting the big tech companies to sacrifice their near-term commercial interests will be an uphill battle. Apple has already removed anti-censorship apps from its Chinese app store.

In 1993, John Gilmore famously said that “The Internet interprets censorship as damage and routes around it.” That was technically true when he said it but only because the routing structure of the Internet was so distributed. As centralization increases, the Internet loses that robustness, and censorship by governments and companies becomes easier.

This essay previously appeared on Lawfare.com.

Posted on June 13, 2018 at 6:55 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.