cell phones Archives - Page 11 of 29

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Page 11 of 29

Stagefright Vulnerability in Android Phones

The Stagefright vulnerability for Android phones is a bad one. It’s exploitable via a text message (details depend on auto downloading of the particular phone), it runs at an elevated privilege (again, the severity depends on the particular phone—on some phones it’s full privilege), and it’s trivial to weaponize. Imagine a worm that infects a phone and then immediately sends a copy of itself to everyone on that phone’s contact list.

The worst part of this is that it’s an Android exploit, so most phones won’t be patched anytime soon—if ever. (The people who discovered the bug alerted Google in April. Google has sent patches to its phone manufacturer partners, but most of them have not sent the patch to Android phone users.)

Posted on July 28, 2015 at 6:37 AM • View Comments

Tracking People By Smart Phone Accelerometers

Interesting research: “We Can Track You If You Take the Metro: Tracking Metro Riders Using Accelerometers on Smartphones“:

Abstract: Motion sensors (e.g., accelerometers) on smartphones have been demonstrated to be a powerful side channel for attackers to spy on users’ inputs on touchscreen. In this paper, we reveal another motion accelerometer-based attack which is particularly serious: when a person takes the metro, a malicious application on her smartphone can easily use accelerator readings to trace her. We first propose a basic attack that can automatically extract metro-related data from a large amount of mixed accelerator readings, and then use an ensemble interval classier built from supervised learning to infer the riding intervals of the user. While this attack is very effective, the supervised learning part requires the attacker to collect labeled training data for each station interval, which is a significant amount of effort. To improve the efficiency of our attack, we further propose a semi-supervised learning approach, which only requires the attacker to collect labeled data for a very small number of station intervals with obvious characteristics. We conduct real experiments on a metro line in a major city. The results show that the inferring accuracy could reach 89% and 92% if the user takes the metro for 4 and 6 stations, respectively.

The Internet of Things is the Internet of sensors. I’m sure all kinds of surveillance is possible from all kinds of sensing inputs.

Posted on June 8, 2015 at 6:09 AM • View Comments

Why the Current Section 215 Reform Debate Doesn't Matter Much

The ACLU’s Chris Soghoian explains (time 25:52-30:55) why the current debate over Section 215 of the Patriot Act is just a minor facet of a large and complex bulk collection program by the FBI and the NSA.

There were 180 orders authorized last year by the FISA Court under Section 215—180 orders issued by this court. Only five of those orders relate to the telephony metadata program. There are 175 orders about completely separate things. In six weeks, Congress will either reauthorize this statute or let it expire, and we’re having a debate—to the extent we’re even having a debate—but the debate that’s taking place is focused on five of the 180, and there’s no debate at all about the other 175 orders.

Now, Senator Wyden has said there are other bulk collection programs targeted at Americans that the public would be shocked to learn about. We don’t know, for example, how the government collects records from Internet providers. We don’t know how they get bulk metadata from tech companies about Americans. We don’t know how the American government gets calling card records.

If we take General Hayden at face value—and I think you’re an honest guy—if the purpose of the 215 program is to identify people who are calling Yemen and Pakistan and Somalia, where one end is in the United States, your average Somali-American is not calling Somalia from their land line phone or their cell phone for the simple reason that AT&T will charge them $7.00 a minute in long distance fees. The way that people in the diaspora call home—the way that people in the Somali or Yemeni community call their family and friends back home—they walk into convenience stores and they buy prepaid calling cards. That is how regular people make international long distance calls.

So the 215 program that has been disclosed publicly, the 215 program that is being debated publicly, is about records to major carriers like AT&T and Verizon. We have not had a debate about surveillance requests, bulk orders to calling card companies, to Skype, to voice over Internet protocol companies. Now, if NSA isn’t collecting those records, they’re not doing their job. I actually think that that’s where the most useful data is. But why are we having this debate about these records that don’t contain a lot of calls to Somalia when we should be having a debate about the records that do contain calls to Somalia and do contain records of e-mails and instant messages and searches and people posting inflammatory videos to YouTube?

Certainly the government is collecting that data, but we don’t know how they’re doing it, we don’t know at what scale they’re doing it, and we don’t know with which authority they’re doing it. And I think it is a farce to say that we’re having a debate about the surveillance authority when really, we’re just debating this very narrow usage of the statute.

Further underscoring this point, yesterday the Department of Justice’s Office of the Inspector General released a redacted version of its internal audit of the FBI’s use of Section 215: “A Review of the FBI’s Use of Section 215 Orders: Assessment of Progress in Implementing Recommendations and Examination of Use in 2007 through 2009,” following the reports of the statute’s use from 2002-2005 and 2006. (Remember that the FBI and the NSA are inexorably connected here. The order to Verizon was from the FBI, requiring it to turn data over to the NSA.)

Details about legal justifications are all in the report (see here for an important point about minimization), but detailed data on exactly what the FBI is collecting—whether targeted or bulk—is left out. We read that the FBI demanded “customer information” (p. 36), “medical and educational records” (p. 39) “account information and electronic communications transactional records” (p. 41), “information regarding other cyber activity” (p. 42). Some of this was undoubtedly targeted against individuals; some of it was undoubtedly bulk.

I believe bulk collection is discussed in detail in Chapter VI. The chapter title is redacted, as well as the introduction (p. 46). Section A is “Bulk Telephony Metadata.” Section B (pp. 59-63) is completely redacted, including the section title. There’s a summary in the Introduction (p. 3): “In Section VI, we update the information about the uses of Section 215 authority described [redacted word] Classified Appendices to our last report. These appendices described the FBI’s use of Section 215 authority on behalf of the NSA to obtain bulk collections of telephony metadata [long redacted clause].” Sounds like a comprehensive discussion of bulk collection under Section 215.

What’s in there? As Soghoian says, certainly other communications systems like prepaid calling cards, Skype, text messaging systems, and e-mails. Search history and browser logs? Financial transactions? The “medical and educational records” mentioned above? Probably all of them—and the data is in the report, redacted (p. 29)—but there’s nothing public.

The problem is that those are the pages Congress should be debating, and not the telephony metadata program exposed by Snowden.

EDITED TO ADD: Marcy Wheeler is going through the document line by line.

Posted on May 22, 2015 at 5:45 AM • View Comments

Another Example of Cell Phone Metadata Forensic Surveillance

Matthew Cole explains how the Italian police figured out how the CIA kidnapped Abu Omar in Milan. Interesting use of cell phone metadata, showing how valuable it is for intelligence purposes.

An Example of Cell Phone Metadata Forensic Surveillance

In this long article on the 2005 assassination of Rafik Hariri in Beirut, there’s a detailed section on what the investigators were able to learn from the cell phone metadata:

At Eid’s request, a judge ordered Lebanon’s two cellphone companies, Alfa and MTC Touch, to produce records of calls and text messages in Lebanon in the four months before the bombing. Eid then studied the records in secret for months. He focused on the phone records of Hariri and his entourage, looking at whom they called, where they went, whom they met and when. He also followed where Adass, the supposed suicide bomber, spent time before he disappeared. He looked at all the calls that took place along the route taken by Hariri’s entourage on the day of the assassination. Always he looked for cause and effect. How did one call lead to the next? “He was brilliant, just brilliant,” the senior U.N. investigator told me. “He himself, on his own, developed a simple but amazingly efficient program to set about mining this massive bank of data.”

The simple algorithm quickly revealed a peculiar pattern. In October 2004, just after Hariri resigned, a certain cluster of cellphones began following him and his now-reduced motorcade wherever they went. These phones stayed close day and night, until the day of the bombing - when nearly all 63 phones in the group immediately went dark and never worked again.

[…]

The investigators now turned their full attention to the cellphone records. Building on Eid’s work, they determined that the assassins worked in groups, each with a leader and each adhering to specific procedures. Everyone in the group called the leader, and he called everyone in the group, but the lower-level operatives never called one another.

The investigators gave each group a color. The green group consisted of 18 Alfa phones, purchased with fake identification from two shops in South Beirut in July and August 2004. The purpose of the fake IDs was not to defraud Alfa out of payment; every month from September 2004 to May 2005, someone went to an Alfa office and paid all 18 bills in cash, without leaving any clue to his identity. The total phone bill for the green network, including activation fees, was $7,375 —a prodigious amount, considering that 15 of the green group’s 18 phones went almost entirely unused.

The first spike in call activity occurred in September 2004, immediately after Hariri announced his resignation. The investigators contend that the green group was at the center of the conspiracy. The phone number 3140023 belonged to the top leader, and the numbers 3159300 and 3150071 belonged to his two deputies. (He called them and they called him, but with those phones, they never called each other.) The two deputies carried phones belonging to other groups, through which they passed on instructions to the other participants in the operation. When a member of one group would call a group leader, the group leader would often follow up by switching to a green phone and calling the supreme leader, who was nearly always in South Beirut, where Hezbollah keeps its headquarters.

On Oct. 20, 2004, the day Hariri left office and his security detail was significantly reduced, the blue group went into operation. It originally worked according to the same rules as the green group, but its active membership increased from three phones to 15, with seven connected to Alfa and eight to MTC Touch. All of the blue phones were prepaid. Some were acquired as early as 2003 and had seen little or no use. The people who bought them also gave false identification, and again money seemed to be in plentiful supply. The minutes that expired each month went largely unused, but the phones were loaded again and again. When the blue group went dark, the phones still had unused minutes worth $4,287.

The prosecutors say the blue group followed Hariri’s movements. On the morning of Oct. 20, its members were already deployed around Quraitem Palace. At 10:30 a.m., Hariri set out toward Parliament and then to the presidential palace, where Lahoud was waiting to receive his resignation. The cell towers picked up the blue group’s members moving with him and calling their chief. From then on, the blue phones trailed Hariri nearly everywhere— to Parliament, to meetings with political leaders, to long lunches at the Saint-Georges Yacht Club & Marina. When Hariri was at his home, so were they. When he flew abroad, they moved with him to the airport and then stopped operating until he returned, when they would pick up the trail again.

Eventually, the yellow group was added….

There’s a lot more. It’s section 6 of the article.

Ears as a Biometric

It’s an obvious biometric for cell phones:

Bodyprint recognizes users by their ears with 99.8% precision with a false rejection rate of only 1 out of 13.

Grip, too.

News story.

EDITED TO ADD: I blogged this in 2011.

Posted on May 1, 2015 at 12:46 PM • View Comments

The Further Democratization of Stingray

Stingray is the code name for an IMSI-catcher, which is basically a fake cell phone tower sold by Harris Corporation to various law enforcement agencies. (It’s actually just one of a series of devices with fish names—Amberjack is another—but it’s the name used in the media.) What is basically does is trick nearby cell phones into connecting to it. Once that happens, the IMSI-catcher can collect identification and location information of the phones and, in some cases, eavesdrop on phone conversations, text messages, and web browsing. (IMSI stands for International Mobile Subscriber Identity, which is the unique serial number your cell phone broadcasts so that the cellular system knows where you are.)

The use of IMSI-catchers in the US used to be a massive police secret. The FBI is so scared of explaining this capability in public that the agency makes local police sign nondisclosure agreements before using the technique, and has instructed them to lie about their use of it in court. When it seemed possible that local police in Sarasota, Florida, might release documents about Stingray cell phone interception equipment to plaintiffs in civil rights litigation against them, federal marshals seized the documents. More recently, St. Louis police dropped a case rather than talk about the technology in court. And Baltimore police admitted using Stingray over 25,000 times.

The truth is that it’s no longer a massive police secret. We now know a lot about IMSI-catchers. And the US government does not have a monopoly over the use of IMSI-catchers. I wrote in Data and Goliath:

There are dozens of these devices scattered around Washington, DC, and the rest of the country run by who-knows-what government or organization. Criminal uses are next.

From the Washington Post:

How rife? Turner and his colleagues assert that their specially outfitted smartphone, called the GSMK CryptoPhone, had detected signs of as many as 18 IMSI catchers in less than two days of driving through the region. A map of these locations, released Wednesday afternoon, looks like a primer on the geography of Washington power, with the surveillance devices reportedly near the White House, the Capitol, foreign embassies and the cluster of federal contractors near Dulles International Airport.

At the RSA Conference last week, Pwnie Express demonstrated their IMSI-catcher detector.

Building your own IMSI-catcher isn’t hard or expensive. At Def Con in 2010, researcher Chris Paget (now Kristin Paget) demonstrated a homemade IMSI-catcher. The whole thing cost $1,500, which is cheap enough for both criminals and nosy hobbyists.

It’s even cheaper and easier now. Anyone with a HackRF software-defined radio card can turn their laptop into an amateur IMSI-catcher. And this is why companies are building detectors into their security monitoring equipment.

Two points here. The first is that the FBI should stop treating Stingray like it’s a big secret, so we can start talking about policy.

The second is that we should stop pretending that this capability is exclusive to law enforcement, and recognize that we’re all at risk because of it. If we continue to allow our cellular networks to be vulnerable to IMSI-catchers, then we are all vulnerable to any foreign government, criminal, hacker, or hobbyist that builds one. If we instead engineer our cellular networks to be secure against this sort of attack, then we are safe against all those attackers.

Me:

We have one infrastructure. We can’t choose a world where the US gets to spy and the Chinese don’t. We get to choose a world where everyone can spy, or a world where no one can spy. We can be secure from everyone, or vulnerable to anyone.

Like QUANTUM, we have the choice of building our cellular infrastructure for security or for surveillance. Let’s choose security.

EDITED TO ADD (5/2): Here’s an IMSI catcher for sale on alibaba.com. At this point, every dictator in the world is using this technology against its own citizens. They’re used extensively in China to send SMS spam without paying the telcos any fees. On a Food Network show called Mystery Diners—episode 108, “Cabin Fever”—someone used an IMSI catcher to intercept a phone call between two restaurant employees.

The new model of the IMSI catcher from Harris Corporation is called Hailstorm. It has the ability to remotely inject malware into cell phones. Other Harris IMSI-catcher codenames are Kingfish, Gossamer, Triggerfish, Amberjack and Harpoon. The competitor is DRT, made by the Boeing subsidiary Digital Receiver Technology, Inc.

EDITED TO ADD (5/2): Here’s an IMSI catcher called Piranha, sold by the Israeli company Rayzone Corp. It claims to work on GSM 2G, 3G, and 4G networks (plus CDMA, of course). The basic Stingray only works on GSM 2G networks, and intercepts phones on the more modern networks by forcing them to downgrade to the 2G protocols. We believe that the more modern ISMI catchers also work against 3G and 4G networks.

EDITED TO ADD (5/13): The FBI recently released more than 5,000 pages of documents about Stingray, but nearly everything is redacted.

Posted on April 27, 2015 at 6:27 AM • View 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?

Take your laptop to a polling place, and sit outside in the parking lot.
Use a free sniffer to capture the traffic, and use that to figure out the WEP password (which VITA did for us).
Connect to the voting machine over WiFi.
If asked for a password, the administrator password is “admin” (VITA provided that).
Download the Microsoft Access database using Windows Explorer.
Use a free tool to extract the hardwired key (“shoup”), which VITA also did for us.
Use Microsoft Access to add, delete, or change any of the votes in the database.
Upload the modified copy of the Microsoft Access database back to the voting machine.
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 AM • View Comments

Cell Phone Opsec

Here’s an article on making secret phone calls with cell phones.

His step-by-step instructions for making a clandestine phone call are as follows:

Analyze your daily movements, paying special attention to anchor points (basis of operation like home or work) and dormant periods in schedules (8-12 p.m. or when cell phones aren’t changing locations);
Leave your daily cell phone behind during dormant periods and purchase a prepaid no-contract cell phone (“burner phone”);
After storing burner phone in a Faraday bag, activate it using a clean computer connected to a public Wi-Fi network;
Encrypt the cell phone number using a onetime pad (OTP) system and rename an image file with the encrypted code. Using Tor to hide your web traffic, post the image to an agreed upon anonymous Twitter account, which signals a communications request to your partner;
Leave cell phone behind, avoid anchor points, and receive phone call from partner on burner phone at 9:30 p.m.—or another pre-arranged “dormant” time—on the following day;
Wipe down and destroy handset.

Note that it actually makes sense to use a one-time pad in this instance. The message is a ten-digit number, and a one-time pad is easier, faster, and cleaner than using any computer encryption program.

Posted on April 7, 2015 at 9:27 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.