Entries Tagged "forensics"

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Dark Web Site Taken Down without Breaking Encryption

The US Department of Justice unraveled a dark web child-porn website, leading to the arrest of 337 people in at least 18 countries. This was all accomplished not through any backdoors in communications systems, but by analyzing the bitcoin transactions and following the money:

Welcome to Video made money by charging fees in bitcoin, and gave each user a unique bitcoin wallet address when they created an account. Son operated the site as a Tor hidden service, a dark web site with a special address that helps mask the identity of the site’s host and its location. But Son and others made mistakes that allowed law enforcement to track them. For example, according to the indictment, very basic assessments of the Welcome to Video website revealed two unconcealed IP addresses managed by a South Korean internet service provider and assigned to an account that provided service to Son’s home address. When agents searched Son’s residence, they found the server running Welcome to Video.

To “follow the money,” as officials put it in Wednesday’s press conference, law enforcement agents sent fairly small amounts of bitcoin­ — roughly equivalent at the time to $125 to $290­ — to the bitcoin wallets Welcome to Video listed for payments. Since the bitcoin blockchain leaves all transactions visible and verifiable, they could observe the currency in these wallets being transferred to another wallet. Law enforcement learned from a bitcoin exchange that the second wallet was registered to Son with his personal phone number and one of his personal email addresses.

Remember this the next time some law enforcement official tells us that they’re powerless to investigate crime without breaking cryptography for everyone.

More news articles. The indictment is here. Some of it is pretty horrifying to read.

Posted on October 25, 2019 at 6:14 AMView Comments

FBI Takes Down a Massive Advertising Fraud Ring

The FBI announced that it dismantled a large Internet advertising fraud network, and arrested eight people:

A 13-count indictment was unsealed today in federal court in Brooklyn charging Aleksandr Zhukov, Boris Timokhin, Mikhail Andreev, Denis Avdeev, Dmitry Novikov, Sergey Ovsyannikov, Aleksandr Isaev and Yevgeniy Timchenko with criminal violations for their involvement in perpetrating widespread digital advertising fraud. The charges include wire fraud, computer intrusion, aggravated identity theft and money laundering. Ovsyannikov was arrested last month in Malaysia; Zhukov was arrested earlier this month in Bulgaria; and Timchenko was arrested earlier this month in Estonia, all pursuant to provisional arrest warrants issued at the request of the United States. They await extradition. The remaining defendants are at large.

It looks like an impressive piece of police work.

Details of the forensics that led to the arrests.

Posted on November 29, 2018 at 6:17 AMView Comments

New Report on Police Digital Forensics Techniques

According to a new CSIS report, “going dark” is not the most pressing problem facing law enforcement in the age of digital data:

Over the past year, we conducted a series of interviews with federal, state, and local law enforcement officials, attorneys, service providers, and civil society groups. We also commissioned a survey of law enforcement officers from across the country to better understand the full range of difficulties they are facing in accessing and using digital evidence in their cases. Survey results indicate that accessing data from service providers — much of which is not encrypted — is the biggest problem that law enforcement currently faces in leveraging digital evidence.

This is a problem that has not received adequate attention or resources to date. An array of federal and state training centers, crime labs, and other efforts have arisen to help fill the gaps, but they are able to fill only a fraction of the need. And there is no central entity responsible for monitoring these efforts, taking stock of the demand, and providing the assistance needed. The key federal entity with an explicit mission to assist state and local law enforcement with their digital evidence needs­ — the National Domestic Communications Assistance Center (NDCAC)­has a budget of $11.4 million, spread among several different programs designed to distribute knowledge about service providers’ poli­cies and products, develop and share technical tools, and train law enforcement on new services and tech­nologies, among other initiatives.

From a news article:

In addition to bemoaning the lack of guidance and help from tech companies — a quarter of survey respondents said their top issue was convincing companies to hand over suspects’ data — law enforcement officials also reported receiving barely any digital evidence training. Local police said they’d received only 10 hours of training in the past 12 months; state police received 13 and federal officials received 16. A plurality of respondents said they only received annual training. Only 16 percent said their organizations scheduled training sessions at least twice per year.

This is a point that Susan Landau has repeatedly made, and also one I make in my new book. The FBI needs technical expertise, not backdoors.

Here’s the report.

Posted on July 27, 2018 at 12:10 PMView Comments

E-Mail Leaves an Evidence Trail

If you’re going to commit an illegal act, it’s best not to discuss it in e-mail. It’s also best to Google tech instructions rather than asking someone else to do it:

One new detail from the indictment, however, points to just how unsophisticated Manafort seems to have been. Here’s the relevant passage from the indictment. I’ve bolded the most important bits:

Manafort and Gates made numerous false and fraudulent representations to secure the loans. For example, Manafort provided the bank with doctored [profit and loss statements] for [Davis Manafort Inc.] for both 2015 and 2016, overstating its income by millions of dollars. The doctored 2015 DMI P&L submitted to Lender D was the same false statement previously submitted to Lender C, which overstated DMI’s income by more than $4 million. The doctored 2016 DMI P&L was inflated by Manafort by more than $3.5 million. To create the false 2016 P&L, on or about October 21, 2016, Manafort emailed Gates a .pdf version of the real 2016 DMI P&L, which showed a loss of more than $600,000. Gates converted that .pdf into a “Word” document so that it could be edited, which Gates sent back to Manafort. Manafort altered that “Word” document by adding more than $3.5 million in income. He then sent this falsified P&L to Gates and asked that the “Word” document be converted back to a .pdf, which Gates did and returned to Manafort. Manafort then sent the falsified 2016 DMI P&L .pdf to Lender D.

So here’s the essence of what went wrong for Manafort and Gates, according to Mueller’s investigation: Manafort allegedly wanted to falsify his company’s income, but he couldn’t figure out how to edit the PDF. He therefore had Gates turn it into a Microsoft Word document for him, which led the two to bounce the documents back-and-forth over email. As attorney and blogger Susan Simpson notes on Twitter, Manafort’s inability to complete a basic task on his own seems to have effectively “created an incriminating paper trail.”

If there’s a lesson here, it’s that the Internet constantly generates data about what people are doing on it, and that data is all potential evidence. The FBI is 100% wrong that they’re going dark; it’s really the golden age of surveillance, and the FBI’s panic is really just its own lack of technical sophistication.

Posted on February 26, 2018 at 3:39 PMView Comments

Daphne Caruana Galizia's Murder and the Security of WhatsApp

Daphne Caruana Galizia was a Maltese journalist whose anti-corruption investigations exposed powerful people. She was murdered in October by a car bomb.

Galizia used WhatsApp to communicate securely with her sources. Now that she is dead, the Maltese police want to break into her phone or the app, and find out who those sources were.

One journalist reports:

Part of Daphne’s destroyed smart phone was elevated from the scene.

Investigators say that Caruana Galizia had not taken her laptop with her on that particular trip. If she had done so, the forensic experts would have found evidence on the ground.

Her mobile phone is also being examined, as can be seen from her WhatsApp profile, which has registered activity since the murder. But it is understood that the data is safe.

Sources close to the newsroom said that as part of the investigation her sim card has been cloned. This is done with the help of mobile service providers in similar cases. Asked if her WhatsApp messages or any other messages that were stored in her phone will be retrieved, the source said that since the messaging application is encrypted, the messages cannot be seen. Therefore it is unlikely that any data can be retrieved.

I am less optimistic than that reporter. The FBI is providing “specific assistance.” The article doesn’t explain that, but I would not be surprised if they were helping crack the phone.

It will be interesting to see if WhatsApp’s security survives this. My guess is that it depends on how much of the phone was recovered from the bombed car.

EDITED TO ADD (11/7): The court-appointed IT expert on the case has a criminal record in the UK for theft and forgery.

Posted on November 6, 2017 at 6:12 AMView Comments

The Future of Forgeries

This article argues that AI technologies will make image, audio, and video forgeries much easier in the future.

Combined, the trajectory of cheap, high-quality media forgeries is worrying. At the current pace of progress, it may be as little as two or three years before realistic audio forgeries are good enough to fool the untrained ear, and only five or 10 years before forgeries can fool at least some types of forensic analysis. When tools for producing fake video perform at higher quality than today’s CGI and are simultaneously available to untrained amateurs, these forgeries might comprise a large part of the information ecosystem. The growth in this technology will transform the meaning of evidence and truth in domains across journalism, government communications, testimony in criminal justice, and, of course, national security.

I am not worried about fooling the “untrained ear,” and more worried about fooling forensic analysis. But there’s an arms race here. Recording technologies will get more sophisticated, too, making their outputs harder to forge. Still, I agree that the advantage will go to the forgers and not the forgery detectors.

Posted on July 10, 2017 at 6:04 AMView Comments

New Paper on Encryption Workarounds

I have written a paper with Orin Kerr on encryption workarounds. Our goal wasn’t to make any policy recommendations. (That was a good thing, since we probably don’t agree on any.) Our goal was to present a taxonomy of different workarounds, and discuss their technical and legal characteristics and complications.

Abstract: The widespread use of encryption has triggered a new step in many criminal investigations: the encryption workaround. We define an encryption workaround as any lawful government effort to reveal an unencrypted version of a target’s data that has been concealed by encryption. This essay provides an overview of encryption workarounds. It begins with a taxonomy of the different ways investigators might try to bypass encryption schemes. We classify six kinds of workarounds: find the key, guess the key, compel the key, exploit a flaw in the encryption software, access plaintext while the device is in use, and locate another plaintext copy. For each approach, we consider the practical, technological, and legal hurdles raised by its use.

The remainder of the essay develops lessons about encryption workarounds and the broader public debate about encryption in criminal investigations. First, encryption workarounds are inherently probabilistic. None work every time, and none can be categorically ruled out every time. Second, the different resources required for different workarounds will have significant distributional effects on law enforcement. Some techniques are inexpensive and can be used often by many law enforcement agencies; some are sophisticated or expensive and likely to be used rarely and only by a few. Third, the scope of legal authority to compel third-party assistance will be a continuing challenge. And fourth, the law governing encryption workarounds remains uncertain and underdeveloped. Whether encryption will be a game-changer or a speed bump depends on both technological change and the resolution of important legal questions that currently remain unanswered.

The paper is finished, but we’ll be revising it once more before final publication. Comments are appreciated.

Posted on March 22, 2017 at 6:23 AMView Comments

Hacking and the 2016 Presidential Election

Was the 2016 presidential election hacked? It’s hard to tell. There were no obvious hacks on Election Day, but new reports have raised the question of whether voting machines were tampered with in three states that Donald Trump won this month: Wisconsin, Michigan and Pennsylvania.

The researchers behind these reports include voting rights lawyer John Bonifaz and J. Alex Halderman, the director of the University of Michigan Center for Computer Security and Society, both respected in the community. They have been talking with Hillary Clinton’s campaign, but their analysis is not yet public.

According to a report in New York magazine, the share of votes received by Clinton was significantly lower in precincts that used a particular type of voting machine: The magazine story suggested that Clinton had received 7 percent fewer votes in Wisconsin counties that used electronic machines, which could be hacked, than in counties that used paper ballots. That is exactly the sort of result we would expect to see if there had been some sort of voting machine hack. There are many different types of voting machines, and attacks against one type would not work against the others. So a voting anomaly correlated to machine type could be a red flag, although Trump did better across the entire Midwest than pre-election polls expected, and there are also some correlations between voting machine type and the demographics of the various precincts. Even Halderman wrote early Wednesday morning that “the most likely explanation is that the polls were systematically wrong, rather than that the election was hacked.”

What the allegations, and the ripples they’re causing on social media, really show is how fundamentally untrustworthy our hodgepodge election system is.

Accountability is a major problem for US elections. The candidates are the ones required to petition for recounts, and we throw the matter into the courts when we can’t figure it out. This all happens after an election, and because the battle lines have already been drawn, the process is intensely political. Unlike many other countries, we don’t have an independent body empowered to investigate these matters. There is no government agency empowered to verify these researchers’ claims, even if it would be merely to reassure voters that the election count was accurate.

Instead, we have a patchwork of voting systems: different rules, different machines, different standards. I’ve seen arguments that there is security in this setup ­ an attacker can’t broadly attack the entire country ­ but the downsides of this system are much more critical. National standards would significantly improve our voting process.

Further investigation of the claims raised by the researchers would help settle this particular question. Unfortunately, time is of the essence ­ underscoring another problem with how we conduct elections. For anything to happen, Clinton has to call for a recount and investigation. She has until Friday to do it in Wisconsin, until Monday in Pennsylvania and until next Wednesday in Michigan. I don’t expect the research team to have any better data before then. Without changes to the system, we’re telling future hackers that they can be successful as long as they’re able to hide their attacks for a few weeks until after the recount deadlines pass.

Computer forensics investigations are not easy, and they’re not quick. They require access to the machines. They involve analysis of Internet traffic. If we suspect a foreign country like Russia, the National Security Agency will analyze what they’ve intercepted from that country. This could easily take weeks, perhaps even months. And in the end, we might not even get a definitive answer. And even if we do end up with evidence that the voting machines were hacked, we don’t have rules about what to do next.

Although winning those three states would flip the election, I predict Clinton will do nothing (her campaign, after all, has reportedly been aware of the researchers’ work for nearly a week). Not because she does not believe the researchers ­- although she might not -­ but because she doesn’t want to throw the post-election process into turmoil by starting a highly politicized process whose eventual outcome will have little to do with computer forensics and a lot to do with which party has more power in the three states.

But we only have two years until the next national elections, and it’s time to start fixing things if we don’t want to be wondering the same things about hackers in 2018. The risks are real: Electronic voting machines that don’t use a paper ballot are vulnerable to hacking.

Clinton supporters are seizing on this story as their last lifeline of hope. I sympathize with them. When I wrote about vote-hacking the day after the election, I said: “Elections serve two purposes. First, and most obvious, they are how we choose a winner. But second, and equally important, they convince the loser ­- and all the supporters ­- that he or she lost.” If the election system fails to do the second, we risk undermining the legitimacy of our democratic process. Clinton’s supporters deserve to know whether this apparent statistical anomaly is the result of a hack against our election system or a spurious correlation. They deserve an election that is demonstrably fair and accurate. Our patchwork, ad hoc system means they may never feel confident in the outcome. And that will further erode the trust we have in our election systems.

This essay previously appeared in the Washington Post.

EDITED TO ADD: Green Party candidate Jill Stein is calling for a recount in the three states. I have no idea if a recount includes forensic analysis to ensure that the machines were not hacked, but I doubt it. It would be funny if it wasn’t all so horrible.

Also, here’s an article from 538.com arguing that demographics explains all the discrepancies.

Posted on November 25, 2016 at 10:00 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.