Entries Tagged "Wi-Fi"

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Using Wi-Fi to Detect Hand Motions and Steal Passwords

This is impressive research: “When CSI Meets Public WiFi: Inferring Your Mobile Phone Password via WiFi Signals“:

Abstract: In this study, we present WindTalker, a novel and practical keystroke inference framework that allows an attacker to infer the sensitive keystrokes on a mobile device through WiFi-based side-channel information. WindTalker is motivated from the observation that keystrokes on mobile devices will lead to different hand coverage and the finger motions, which will introduce a unique interference to the multi-path signals and can be reflected by the channel state information (CSI). The adversary can exploit the strong correlation between the CSI fluctuation and the keystrokes to infer the user’s number input. WindTalker presents a novel approach to collect the target’s CSI data by deploying a public WiFi hotspot. Compared with the previous keystroke inference approach, WindTalker neither deploys external devices close to the target device nor compromises the target device. Instead, it utilizes the public WiFi to collect user’s CSI data, which is easy-to-deploy and difficult-to-detect. In addition, it jointly analyzes the traffic and the CSI to launch the keystroke inference only for the sensitive period where password entering occurs. WindTalker can be launched without the requirement of visually seeing the smart phone user’s input process, backside motion, or installing any malware on the tablet. We implemented Windtalker on several mobile phones and performed a detailed case study to evaluate the practicality of the password inference towards Alipay, the largest mobile payment platform in the world. The evaluation results show that the attacker can recover the key with a high successful rate.

That “high successful rate” is 81.7%.

News article.

Posted on November 18, 2016 at 6:40 AMView Comments

Using Wi-Fi Signals to Identify People by Body Shape

Another paper on using Wi-Fi for surveillance. This one is on identifying people by their body shape. “FreeSense:Indoor Human Identification with WiFi Signals“:

Abstract: Human identification plays an important role in human-computer interaction. There have been numerous methods proposed for human identification (e.g., face recognition, gait recognition, fingerprint identification, etc.). While these methods could be very useful under different conditions, they also suffer from certain shortcomings (e.g., user privacy, sensing coverage range). In this paper, we propose a novel approach for human identification, which leverages WIFI signals to enable non-intrusive human identification in domestic environments. It is based on the observation that each person has specific influence patterns to the surrounding WIFI signal while moving indoors, regarding their body shape characteristics and motion patterns. The influence can be captured by the Channel State Information (CSI) time series of WIFI. Specifically, a combination of Principal Component Analysis (PCA), Discrete Wavelet Transform (DWT) and Dynamic Time Warping (DTW) techniques is used for CSI waveform-based human identification. We implemented the system in a 6m*5m smart home environment and recruited 9 users for data collection and evaluation. Experimental results indicate that the identification accuracy is about 88.9% to 94.5% when the candidate user set changes from 6 to 2, showing that the proposed human identification method is effective in domestic environments.

EDITED TO ADD (9/13): Related paper.

Posted on August 30, 2016 at 12:57 PMView Comments

Keystroke Recognition from Wi-Fi Distortion

This is interesting research: “Keystroke Recognition Using WiFi Signals.” Basically, the user’s hand positions as they type distorts the Wi-Fi signal in predictable ways.

Abstract: Keystroke privacy is critical for ensuring the security of computer systems and the privacy of human users as what being typed could be passwords or privacy sensitive information. In this paper, we show for the first time that WiFi signals
can also be exploited to recognize keystrokes. The intuition is that while typing a certain key, the hands and fingers of a user move in a unique formation and direction and thus generate a unique pattern in the time-series of Channel State Information (CSI) values, which we call CSI-waveform for that key. In this paper, we propose a WiFi signal based keystroke recognition system called WiKey. WiKey consists of two Commercial Off-The-Shelf (COTS) WiFi devices, a sender (such as a router) and a receiver (such as a laptop). The sender continuously emits signals and the receiver continuously receives signals. When a human subject types on a keyboard, WiKey recognizes the typed keys based on how the CSI values at the WiFi signal receiver end. We implemented the WiKey system using a TP-Link TL-WR1043ND WiFi router and a Lenovo X200 laptop. WiKey achieves more than 97.5% detection rate for detecting the keystroke and 96.4% recognition accuracy for classifying single keys. In real-world experiments, WiKey can recognize keystrokes in a continuously typed sentence with an accuracy of 93.5%.

News article.

Posted on August 30, 2016 at 6:04 AMView Comments

Bizarre High-Tech Kidnapping

This is a story of a very high-tech kidnapping:

FBI court filings unsealed last week showed how Denise Huskins’ kidnappers used anonymous remailers, image sharing sites, Tor, and other people’s Wi-Fi to communicate with the police and the media, scrupulously scrubbing meta data from photos before sending. They tried to use computer spyware and a DropCam to monitor the aftermath of the abduction and had a Parrot radio-controlled drone standing by to pick up the ransom by remote control.

The story also demonstrates just how effective the FBI is tracing cell phone usage these days. They had a blocked call from the kidnappers to the victim’s cell phone. First they used a search warrant to AT&T to get the actual calling number. After learning that it was an AT&T prepaid Tracfone, they called AT&T to find out where the burner was bought, what the serial numbers were, and the location where the calls were made from.

The FBI reached out to Tracfone, which was able to tell the agents that the phone was purchased from a Target store in Pleasant Hill on March 2 at 5:39 pm. Target provided the bureau with a surveillance-cam photo of the buyer: a white male with dark hair and medium build. AT&T turned over records showing the phone had been used within 650 feet of a cell site in South Lake Tahoe.

Here’s the criminal complaint. It borders on surreal. Were it an episode of CSI:Cyber, you would never believe it.

Posted on July 29, 2015 at 6:34 AMView Comments

New RC4 Attack

New research: “All Your Biases Belong To Us: Breaking RC4 in WPA-TKIP and TLS,” by Mathy Vanhoef and Frank Piessens:

Abstract: We present new biases in RC4, break the Wi-Fi Protected Access Temporal Key Integrity Protocol (WPA-TKIP), and design a practical plaintext recovery attack against the Transport Layer Security (TLS) protocol. To empirically find new biases in the RC4 keystream we use statistical hypothesis tests. This reveals many new biases in the initial keystream bytes, as well as several new long-term biases. Our fixed-plaintext recovery algorithms are capable of using multiple types of biases, and return a list of plaintext candidates in decreasing likelihood.

To break WPA-TKIP we introduce a method to generate a large number of identical packets. This packet is decrypted by generating its plaintext candidate list, and using redundant packet structure to prune bad candidates. From the decrypted packet we derive the TKIP MIC key, which can be used to inject and decrypt packets. In practice the attack can be executed within an hour. We also attack TLS as used by HTTPS, where we show how to decrypt a secure cookie with a success rate of 94% using 9*227 ciphertexts. This is done by injecting known data around the cookie, abusing this using Mantin’s ABSAB bias, and brute-forcing the cookie by traversing the plaintext candidates. Using our traffic generation technique, we are able to execute the attack in merely 75 hours.

News articles.

We need to deprecate the algorithm already.

Posted on July 28, 2015 at 12:09 PMView Comments

An Incredibly Insecure Voting Machine

Wow:

The weak passwords—which are hard-coded and can’t be changed—were only one item on a long list of critical defects uncovered by the review. The Wi-Fi network the machines use is encrypted with wired equivalent privacy, an algorithm so weak that it takes as little as 10 minutes for attackers to break a network’s encryption key. The shortcomings of WEP have been so well-known that it was banished in 2004 by the IEEE, the world’s largest association of technical professionals. What’s more, the WINVote runs a version of Windows XP Embedded that hasn’t received a security patch since 2004, making it vulnerable to scores of known exploits that completely hijack the underlying machine. Making matters worse, the machine uses no firewall and exposes several important Internet ports.

It’s the AVS WinVote touchscreen Direct Recording Electronic (DRE). The Virginia Information Technology Agency (VITA) investigated the machine, and found that you could hack this machine from across the street with a smart phone:

So how would someone use these vulnerabilities to change an election?

  1. Take your laptop to a polling place, and sit outside in the parking lot.
  2. Use a free sniffer to capture the traffic, and use that to figure out the WEP password (which VITA did for us).
  3. Connect to the voting machine over WiFi.
  4. If asked for a password, the administrator password is “admin” (VITA provided that).
  5. Download the Microsoft Access database using Windows Explorer.
  6. Use a free tool to extract the hardwired key (“shoup”), which VITA also did for us.
  7. Use Microsoft Access to add, delete, or change any of the votes in the database.
  8. Upload the modified copy of the Microsoft Access database back to the voting machine.
  9. Wait for the election results to be published.

Note that none of the above steps, with the possible exception of figuring out the WEP password, require any technical expertise. In fact, they’re pretty much things that the average office worker does on a daily basis.

More.

Posted on April 23, 2015 at 7:19 AMView Comments

Hacking Airplanes

Imagine this: A terrorist hacks into a commercial airplane from the ground, takes over the controls from the pilots and flies the plane into the ground. It sounds like the plot of some “Die Hard” reboot, but it’s actually one of the possible scenarios outlined in a new Government Accountability Office report on security vulnerabilities in modern airplanes.

It’s certainly possible, but in the scheme of Internet risks I worry about, it’s not very high. I’m more worried about the more pedestrian attacks against more common Internet-connected devices. I’m more worried, for example, about a multination cyber arms race that stockpiles capabilities such as this, and prioritizes attack over defense in an effort to gain relative advantage. I worry about the democratization of cyberattack techniques, and who might have the capabilities currently reserved for nation-states. And I worry about a future a decade from now if these problems aren’t addressed.

First, the airplanes. The problem the GAO identifies is one computer security experts have talked about for years. Newer planes such as the Boeing 787 Dreamliner and the Airbus A350 and A380 have a single network that is used both by pilots to fly the plane and passengers for their Wi-Fi connections. The risk is that a hacker sitting in the back of the plane, or even one on the ground, could use the Wi-Fi connection to hack into the avionics and then remotely fly the plane.

The report doesn’t explain how someone could do this, and there are currently no known vulnerabilities that a hacker could exploit. But all systems are vulnerable—we simply don’t have the engineering expertise to design and build perfectly secure computers and networks—so of course we believe this kind of attack is theoretically possible.

Previous planes had separate networks, which is much more secure.

As terrifying as this movie-plot threat is—and it has been the plot of several recent works of fiction—this is just one example of an increasingly critical problem: As the computers already critical to running our infrastructure become connected, our vulnerability to cyberattack grows. We’ve already seen vulnerabilities in baby monitors, cars, medical equipment and all sorts of other Internet-connected devices. In February, Toyota recalled 1.9 million Prius cars because of a software vulnerability. Expect similar vulnerabilities in our smart thermostats, smart light bulbs and everything else connected to the smart power grid. The Internet of Things will bring computers into every aspect of our life and society. Those computers will be on the network and will be vulnerable to attack.

And because they’ll all be networked together, a vulnerability in one device will affect the security of everything else. Right now, a vulnerability in your home router can compromise the security of your entire home network. A vulnerability in your Internet-enabled refrigerator can reportedly be used as a launching pad for further attacks.

Future attacks will be exactly like what’s happening on the Internet today with your computer and smartphones, only they will be with everything. It’s all one network, and it’s all critical infrastructure.

Some of these attacks will require sufficient budget and organization to limit them to nation-state aggressors. But that’s hardly comforting. North Korea is last year believed to have launched a massive cyberattack against Sony Pictures. Last month, China used a cyberweapon called the “Great Cannon” against the website GitHub. In 2010, the U.S. and Israeli governments launched a sophisticated cyberweapon called Stuxnet against the Iranian Natanz nuclear power plant; it used a series of vulnerabilities to cripple centrifuges critical for separating nuclear material. In fact, the United States has done more to weaponize the Internet than any other country.

Governments only have a fleeting advantage over everyone else, though. Today’s top-secret National Security Agency programs become tomorrow’s Ph.D. theses and the next day’s hacker’s tools. So while remotely hacking the 787 Dreamliner’s avionics might be well beyond the capabilities of anyone except Boeing engineers today, that’s not going to be true forever.

What this all means is that we have to start thinking about the security of the Internet of Things—whether the issue in question is today’s airplanes or tomorrow’s smart clothing. We can’t repeat the mistakes of the early days of the PC and then the Internet, where we initially ignored security and then spent years playing catch-up. We have to build security into everything that is going to be connected to the Internet.

This is going to require both significant research and major commitments by companies. It’s also going to require legislation mandating certain levels of security on devices connecting to the Internet, and at network providers that make the Internet work. This isn’t something the market can solve on its own, because there are just too many incentives to ignore security and hope that someone else will solve it.

As a nation, we need to prioritize defense over offense. Right now, the NSA and U.S. Cyber Command have a strong interest in keeping the Internet insecure so they can better eavesdrop on and attack our enemies. But this prioritization cuts both ways: We can’t leave others’ networks vulnerable without also leaving our own vulnerable. And as one of the most networked countries on the planet, we are highly vulnerable to attack. It would be better to focus the NSA’s mission on defense and harden our infrastructure against attack.

Remember the GAO’s nightmare scenario: A hacker on the ground exploits a vulnerability in the airplane’s Wi-Fi system to gain access to the airplane’s network. Then he exploits a vulnerability in the firewall that separates the passengers’ network from the avionics to gain access to the flight controls. Then he uses other vulnerabilities both to lock the pilots out of the cockpit controls and take control of the plane himself.

It’s a scenario made possible by insecure computers and insecure networks. And while it might take a government-led secret project on the order of Stuxnet to pull it off today, that won’t always be true.

Of course, this particular movie-plot threat might never become a real one. But it is almost certain that some equally unlikely scenario will. I just hope we have enough security expertise to deal with whatever it ends up being.

This essay originally appeared on CNN.com.

EDITED TO ADD: News articles.

Posted on April 21, 2015 at 1:40 PMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.