Blog: April 2020 Archives

Securing Internet Videoconferencing Apps: Zoom and Others

The NSA just published a survey of video conferencing apps. So did Mozilla.

Zoom is on the good list, with some caveats. The company has done a lot of work addressing previous security concerns. It still has a bit to go on end-to-end encryption. Matthew Green looked at this. Zoom does offer end-to-end encryption if 1) everyone is using a Zoom app, and not logging in to the meeting using a webpage, and 2) the meeting is not being recorded in the cloud. That’s pretty good, but the real worry is where the encryption keys are generated and stored. According to Citizen Lab, the company generates them.

The Zoom transport protocol adds Zoom’s own encryption scheme to RTP in an unusual way. By default, all participants’ audio and video in a Zoom meeting appears to be encrypted and decrypted with a single AES-128 key shared amongst the participants. The AES key appears to be generated and distributed to the meeting’s participants by Zoom servers. Zoom’s encryption and decryption use AES in ECB mode, which is well-understood to be a bad idea, because this mode of encryption preserves patterns in the input.

The algorithm part was just fixed:

AES 256-bit GCM encryption: Zoom is upgrading to the AES 256-bit GCM encryption standard, which offers increased protection of your meeting data in transit and resistance against tampering. This provides confidentiality and integrity assurances on your Zoom Meeting, Zoom Video Webinar, and Zoom Phone data. Zoom 5.0, which is slated for release within the week, supports GCM encryption, and this standard will take effect once all accounts are enabled with GCM. System-wide account enablement will take place on May 30.

There is nothing in Zoom’s latest announcement about key management. So: while the company has done a really good job improving the security and privacy of their platform, there seems to be just one step remaining to fully encrypt the sessions.

The other thing I want Zoom to do is to make the security options necessary to prevent Zoombombing to be made available to users of the free version of that platform. Forcing users to pay for security isn’t a viable option right now.

Finally — I use Zoom all the time. I finished my Harvard class using Zoom; it’s the university standard. I am having Inrupt company meetings on Zoom. I am having professional and personal conferences on Zoom. It’s what everyone has, and the features are really good.

Posted on April 30, 2020 at 10:24 AM32 Comments

How Did Facebook Beat a Federal Wiretap Demand?

This is interesting:

Facebook Inc. in 2018 beat back federal prosecutors seeking to wiretap its encrypted Messenger app. Now the American Civil Liberties Union is seeking to find out how.

The entire proceeding was confidential, with only the result leaking to the press. Lawyers for the ACLU and the Washington Post on Tuesday asked a San Francisco-based federal court of appeals to unseal the judge’s decision, arguing the public has a right to know how the law is being applied, particularly in the area of privacy.

[…]

The Facebook case stems from a federal investigation of members of the violent MS-13 criminal gang. Prosecutors tried to hold Facebook in contempt after the company refused to help investigators wiretap its Messenger app, but the judge ruled against them. If the decision is unsealed, other tech companies will likely try to use its reasoning to ward off similar government requests in the future.

Here’s the 2018 story. Slashdot thread.

Posted on April 29, 2020 at 12:29 PM13 Comments

Fooling NLP Systems Through Word Swapping

MIT researchers have built a system that fools natural-language processing systems by swapping words with synonyms:

The software, developed by a team at MIT, looks for the words in a sentence that are most important to an NLP classifier and replaces them with a synonym that a human would find natural. For example, changing the sentence “The characters, cast in impossibly contrived situations, are totally estranged from reality” to “The characters, cast in impossibly engineered circumstances, are fully estranged from reality” makes no real difference to how we read it. But the tweaks made an AI interpret the sentences completely differently.

The results of this adversarial machine learning attack are impressive:

For example, Google’s powerful BERT neural net was worse by a factor of five to seven at identifying whether reviews on Yelp were positive or negative.

The paper:

Abstract: Machine learning algorithms are often vulnerable to adversarial examples that have imperceptible alterations from the original counterparts but can fool the state-of-the-art models. It is helpful to evaluate or even improve the robustness of these models by exposing the maliciously crafted adversarial examples. In this paper, we present TextFooler, a simple but strong baseline to generate natural adversarial text. By applying it to two fundamental natural language tasks, text classification and textual entailment, we successfully attacked three target models, including the powerful pre-trained BERT, and the widely used convolutional and recurrent neural networks. We demonstrate the advantages of this framework in three ways: (1) effective — it outperforms state-of-the-art attacks in terms of success rate and perturbation rate, (2) utility-preserving — it preserves semantic content and grammaticality, and remains correctly classified by humans, and (3) efficient — it generates adversarial text with computational complexity linear to the text length.

EDITED TO ADD: This post has been translated into Spanish.

Posted on April 28, 2020 at 10:38 AM48 Comments

Automatic Instacart Bots

Instacart is taking legal action against bots that automatically place orders:

Before it closed, to use Cartdash users first selected what items they want from Instacart as normal. Once that was done, they had to provide Cartdash with their Instacart email address, password, mobile number, tip amount, and whether they prefer the first available delivery slot or are more flexible. The tool then checked that their login credentials were correct, logged in, and refreshed the checkout page over and over again until a new delivery window appeared. It then placed the order, Koch explained.

I think I am writing a new book about hacking in general, and want to discuss this. First, does this count as a hack? I feel like it is, since it’s a way to subvert the Instacart ordering system.

When asked if this tool may give people an unfair advantage over those who don’t use the tool, Koch said, “at this point, it’s a matter of awareness, not technical ability, since people who can use Instacart can use Cartdash.” When pushed on how, realistically, not every user of Instacart is going to know about Cartdash, even after it may receive more attention, and the people using Cartdash will still have an advantage over people who aren’t using automated tools, Koch again said, “it’s a matter of awareness, not technical ability.”

Second, should Instacart take action against this? On the one hand, it isn’t “fair” in that Cartdash users get an advantage in finding a delivery slot. But it’s not really any different than programs that “snipe” on eBay and other bidding platforms.

Third, does Instacart even stand a chance in the long run. As various AI technologies give us more agents and bots, this is going to increasingly become the new normal. I think we need to figure out a fair allocation mechanism that doesn’t rely on the precise timing of submissions.

Posted on April 27, 2020 at 6:13 AM44 Comments

Friday Squid Blogging: Humboldt Squid Backlight Themselves to Communicate More Clearly

This is neat:

Deep in the Pacific Ocean, six-foot-long Humboldt squid are known for being aggressive, cannibalistic and, according to new research, good communicators.

Known as “red devils,” the squid can rapidly change the color of their skin, making different patterns to communicate, something other squid species are known to do.

But Humboldt squid live in almost total darkness more than 1,000 feet below the surface, so their patterns aren’t very visible. Instead, according to a new study, they create backlighting for the patterns by making their bodies glow, like the screen of an e-reader.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Read my blog posting guidelines here.

Posted on April 24, 2020 at 4:15 PM86 Comments

Global Surveillance in the Wake of COVID-19

OneZero is tracking thirty countries around the world who are implementing surveillance programs in the wake of COVID-19:

The most common form of surveillance implemented to battle the pandemic is the use of smartphone location data, which can track population-level movement down to enforcing individual quarantines. Some governments are making apps that offer coronavirus health information, while also sharing location information with authorities for a period of time. For instance, in early March, the Iranian government released an app that it pitched as a self-diagnostic tool. While the tool’s efficacy was likely low, given reports of asymptomatic carriers of the virus, the app saved location data of millions of Iranians, according to a Vice report.

One of the most alarming measures being implemented is in Argentina, where those who are caught breaking quarantine are being forced to download an app that tracks their location. In Hong Kong, those arriving in the airport are given electronic tracking bracelets that must be synced to their home location through their smartphone’s GPS signal.

Posted on April 24, 2020 at 6:02 AM62 Comments

Chinese COVID-19 Disinformation Campaign

The New York Times is reporting on state-sponsored disinformation campaigns coming out of China:

Since that wave of panic, United States intelligence agencies have assessed that Chinese operatives helped push the messages across platforms, according to six American officials, who spoke on the condition of anonymity to publicly discuss intelligence matters. The amplification techniques are alarming to officials because the disinformation showed up as texts on many Americans’ cellphones, a tactic that several of the officials said they had not seen before.

Posted on April 23, 2020 at 12:01 PM19 Comments

New iPhone Zero-Day Discovered

Last year, ZecOps discovered two iPhone zero-day exploits. They will be patched in the next iOS release:

Avraham declined to disclose many details about who the targets were, and did not say whether they lost any data as a result of the attacks, but said “we were a bit surprised about who was targeted.” He said some of the targets were an executive from a telephone carrier in Japan, a “VIP” from Germany, managed security service providers from Saudi Arabia and Israel, people who work for a Fortune 500 company in North America, and an executive from a Swiss company.

[…]

On the other hand, this is not as polished a hack as others, as it relies on sending an oversized email, which may get blocked by certain email providers. Moreover, Avraham said it only works on the default Apple Mail app, and not on Gmail or Outlook, for example.

Posted on April 22, 2020 at 9:12 AM14 Comments

Another Story of Bad 1970s Encryption

This one is from the Netherlands. It seems to be clever cryptanalysis rather than a backdoor.

The Dutch intelligence service has been able to read encrypted communications from dozens of countries since the late 1970s thanks to a microchip, according to research by de Volkskrant on Thursday. The Netherlands could eavesdrop on confidential communication from countries such as Iran, Egypt and Saudi Arabia.

Philips, together with Siemens, built an encryption machine in the late 1970s. The device, the Aroflex, was used for secret communication between NATO allies. In addition, the companies also wanted to market the T1000CA, a commercial variant of the Aroflex with less strong cryptography.

The Volkskrant investigation shows that the Ministry of Foreign Affairs and the Marine Intelligence Service (MARID) cracked the cryptography of this device before it was launched. Philips helped the ministry and the intelligence service.

Normally it would take at least a month and a half to crack the T1000CA encryption. “Too long to get useful information from intercepted communication,” the newspaper writes. But MARID employees, together with Philips, succeeded in accelerating this 2.500 times by developing a special microchip.

The T1000CA was then sold to numerous non-NATO countries, including the Middle East and Asia. These countries could then be overheard by the Dutch intelligence services for years.

The 1970s was a decade of really bad commercial cryptography. DES, in 1975, was an improvement with its 56-bit key. I’m sure there are lots of these stories.

Here’s more about the Aroflex. And here’s what I think is the original Dutch story.

Posted on April 21, 2020 at 6:22 AM14 Comments

Vulnerability Finding Using Machine Learning

Microsoft is training a machine-learning system to find software bugs:

At Microsoft, 47,000 developers generate nearly 30 thousand bugs a month. These items get stored across over 100 AzureDevOps and GitHub repositories. To better label and prioritize bugs at that scale, we couldn’t just apply more people to the problem. However, large volumes of semi-curated data are perfect for machine learning. Since 2001 Microsoft has collected 13 million work items and bugs. We used that data to develop a process and machine learning model that correctly distinguishes between security and non-security bugs 99 percent of the time and accurately identifies the critical, high priority security bugs, 97 percent of the time.

News article.

I wrote about this in 2018:

The problem of finding software vulnerabilities seems well-suited for ML systems. Going through code line by line is just the sort of tedious problem that computers excel at, if we can only teach them what a vulnerability looks like. There are challenges with that, of course, but there is already a healthy amount of academic literature on the topic — and research is continuing. There’s every reason to expect ML systems to get better at this as time goes on, and some reason to expect them to eventually become very good at it.

Finding vulnerabilities can benefit both attackers and defenders, but it’s not a fair fight. When an attacker’s ML system finds a vulnerability in software, the attacker can use it to compromise systems. When a defender’s ML system finds the same vulnerability, he or she can try to patch the system or program network defenses to watch for and block code that tries to exploit it.

But when the same system is in the hands of a software developer who uses it to find the vulnerability before the software is ever released, the developer fixes it so it can never be used in the first place. The ML system will probably be part of his or her software design tools and will automatically find and fix vulnerabilities while the code is still in development.

Fast-forward a decade or so into the future. We might say to each other, “Remember those years when software vulnerabilities were a thing, before ML vulnerability finders were built into every compiler and fixed them before the software was ever released? Wow, those were crazy years.” Not only is this future possible, but I would bet on it.

Getting from here to there will be a dangerous ride, though. Those vulnerability finders will first be unleashed on existing software, giving attackers hundreds if not thousands of vulnerabilities to exploit in real-world attacks. Sure, defenders can use the same systems, but many of today’s Internet of Things (IoT) systems have no engineering teams to write patches and no ability to download and install patches. The result will be hundreds of vulnerabilities that attackers can find and use.

Posted on April 20, 2020 at 6:22 AM27 Comments

The DoD Isn't Fixing Its Security Problems

It has produced several reports outlining what’s wrong and what needs to be fixed. It’s not fixing them:

GAO looked at three DoD-designed initiatives to see whether the Pentagon is following through on its own goals. In a majority of cases, DoD has not completed the cybersecurity training and awareness tasks it set out to. The status of various efforts is simply unknown because no one has tracked their progress. While an assessment of “cybersecurity hygiene” like this doesn’t directly analyze a network’s hardware and software vulnerabilities, it does underscore the need for people who use digital systems to interact with them in secure ways. Especially when those people work on national defense.

[…]

The report focuses on three ongoing DoD cybersecurity hygiene initiatives. The 2015 Cybersecurity Culture and Compliance Initiative outlined 11 education-related goals for 2016; the GAO found that the Pentagon completed only four of them. Similarly, the 2015 Cyber Discipline plan outlined 17 goals related to detecting and eliminating preventable vulnerabilities from DoD’s networks by the end of 2018. GAO found that DoD has met only six of those. Four are still pending, and the status of the seven others is unknown, because no one at DoD has kept track of the progress.

GAO repeatedly identified lack of status updates and accountability as core issues within DoD’s cybersecurity awareness and education efforts. It was unclear in many cases who had completed which training modules. There were even DoD departments lacking information on which users should have their network access revoked for failure to complete trainings.

The report.

Posted on April 17, 2020 at 10:35 AM13 Comments

California Needlessly Reduces Privacy During COVID-19 Pandemic

This one isn’t even related to contact tracing:

On March 17, 2020, the federal government relaxed a number of telehealth-related regulatory requirements due to COVID-19. On April 3, 2020, California Governor Gavin Newsom issued Executive Order N-43-20 (the Order), which relaxes various telehealth reporting requirements, penalties, and enforcements otherwise imposed under state laws, including those associated with unauthorized access and disclosure of personal information through telehealth mediums.

Lots of details at the link.

Posted on April 16, 2020 at 10:34 AM22 Comments

Ransomware Now Leaking Stolen Documents

Originally, ransomware didn’t involve any data theft. Malware would encrypt the data on your computer, and demand a ransom for the encryption key. Now ransomware is increasingly involving both encryption and exfiltration. Brian Krebs wrote about this in December. It’s a further incentive for the victims to pay.

Recently, the aerospace company Visser Precision was hit by the DoppelPaymer ransomware. The company refused to pay, so the criminals leaked documents and data belonging to Visser Precision, Lockheed Martin, Boeing, SpaceX, the US Navy, and others.

Posted on April 14, 2020 at 7:48 AM15 Comments

Contact Tracing COVID-19 Infections via Smartphone Apps

Google and Apple have announced a joint project to create a privacy-preserving COVID-19 contact tracing app. (Details, such as we have them, are here.) It’s similar to the app being developed at MIT, and similar to others being described and developed elsewhere. It’s nice seeing the privacy protections; they’re well thought out.

I was going to write a long essay about the security and privacy concerns, but Ross Anderson beat me to it. (Note that some of his comments are UK-specific.)

First, it isn’t anonymous. Covid-19 is a notifiable disease so a doctor who diagnoses you must inform the public health authorities, and if they have the bandwidth they call you and ask who you’ve been in contact with. They then call your contacts in turn. It’s not about consent or anonymity, so much as being persuasive and having a good bedside manner.

I’m relaxed about doing all this under emergency public-health powers, since this will make it harder for intrusive systems to persist after the pandemic than if they have some privacy theater that can be used to argue that the whizzy new medi-panopticon is legal enough to be kept running.

Second, contact tracers have access to all sorts of other data such as public transport ticketing and credit-card records. This is how a contact tracer in Singapore is able to phone you and tell you that the taxi driver who took you yesterday from Orchard Road to Raffles has reported sick, so please put on a mask right now and go straight home. This must be controlled; Taiwan lets public-health staff access such material in emergencies only.

Third, you can’t wait for diagnoses. In the UK, you only get a test if you’re a VIP or if you get admitted to hospital. Even so the results take 1-3 days to come back. While the VIPs share their status on twitter or facebook, the other diagnosed patients are often too sick to operate their phones.

Fourth, the public health authorities need geographical data for purposes other than contact tracing – such as to tell the army where to build more field hospitals, and to plan shipments of scarce personal protective equipment. There are already apps that do symptom tracking but more would be better. So the UK app will ask for the first three characters of your postcode, which is about enough to locate which hospital you’d end up in.

Fifth, although the cryptographers – and now Google and Apple – are discussing more anonymous variants of the Singapore app, that’s not the problem. Anyone who’s worked on abuse will instantly realise that a voluntary app operated by anonymous actors is wide open to trolling. The performance art people will tie a phone to a dog and let it run around the park; the Russians will use the app to run service-denial attacks and spread panic; and little Johnny will self-report symptoms to get the whole school sent home.

I recommend reading his essay in full. Also worth reading are this EFF essay, and this ACLU white paper.

To me, the real problems aren’t around privacy and security. The efficacy of any app-based contact tracing is still unproven. A “contact” from the point of view of an app isn’t the same as an epidemiological contact. And the ratio of infections to contacts is high. We would have to deal with the false positives (being close to someone else, but separated by a partition or other barrier) and the false negatives (not being close to someone else, but contracting the disease through a mutually touched object). And without cheap, fast, and accurate testing, the information from any of these apps isn’t very useful. So I agree with Ross that this is primarily an exercise in that false syllogism: Something must be done. This is something. Therefore, we must do it. It’s techies proposing tech solutions to what is primarily a social problem.

EDITED TO ADD: Susan Landau on contact tracing apps and how they’re being oversold. And Farzad Mostashari, former coordinator for health IT at the Department of Health and Human Services, on contact tracing apps.

As long as 1) every contact does not result in an infection, and 2) a large percentage of people with the disease are asymptomatic and don’t realize they have it, I can’t see how this sort of app is valuable. If we had cheap, fast, and accurate testing for everyone on demand…maybe. But I still don’t think so.

EDITED TO ADD (4/15): More details from Apple and Google.

EDITED TO ADD (4/19): Apple and Google have strengthened the security and privacy of their system.

Posted on April 13, 2020 at 6:48 AM65 Comments

Microsoft Buys Corp.com

A few months ago, Brian Krebs told the story of the domain corp.com, and how it is basically a security nightmare:

At issue is a problem known as “namespace collision,” a situation where domain names intended to be used exclusively on an internal company network end up overlapping with domains that can resolve normally on the open Internet.

Windows computers on an internal corporate network validate other things on that network using a Microsoft innovation called Active Directory, which is the umbrella term for a broad range of identity-related services in Windows environments. A core part of the way these things find each other involves a Windows feature called “DNS name devolution,” which is a kind of network shorthand that makes it easier to find other computers or servers without having to specify a full, legitimate domain name for those resources.

For instance, if a company runs an internal network with the name internalnetwork.example.com, and an employee on that network wishes to access a shared drive called “drive1,” there’s no need to type “drive1.internalnetwork.example.com” into Windows Explorer; typing “\\drive1\” alone will suffice, and Windows takes care of the rest.

But things can get far trickier with an internal Windows domain that does not map back to a second-level domain the organization actually owns and controls. And unfortunately, in early versions of Windows that supported Active Directory — Windows 2000 Server, for example — the default or example Active Directory path was given as “corp,” and many companies apparently adopted this setting without modifying it to include a domain they controlled.

Compounding things further, some companies then went on to build (and/or assimilate) vast networks of networks on top of this erroneous setting.

Now, none of this was much of a security concern back in the day when it was impractical for employees to lug their bulky desktop computers and monitors outside of the corporate network. But what happens when an employee working at a company with an Active Directory network path called “corp” takes a company laptop to the local Starbucks?

Chances are good that at least some resources on the employee’s laptop will still try to access that internal “corp” domain. And because of the way DNS name devolution works on Windows, that company laptop online via the Starbucks wireless connection is likely to then seek those same resources at “corp.com.”

In practical terms, this means that whoever controls corp.com can passively intercept private communications from hundreds of thousands of computers that end up being taken outside of a corporate environment which uses this “corp” designation for its Active Directory domain.

Microsoft just bought it, so it wouldn’t fall into the hands of any bad actors:

In a written statement, Microsoft said it acquired the domain to protect its customers.

“To help in keeping systems protected we encourage customers to practice safe security habits when planning for internal domain and network names,” the statement reads. “We released a security advisory in June of 2009 and a security update that helps keep customers safe. In our ongoing commitment to customer security, we also acquired the Corp.com domain.”

Posted on April 9, 2020 at 6:45 AM16 Comments

RSA-250 Factored

RSA-250 has been factored.

This computation was performed with the Number Field Sieve algorithm,
using the open-source CADO-NFS software.

The total computation time was roughly 2700 core-years, using Intel Xeon Gold 6130 CPUs as a reference (2.1GHz):

RSA-250 sieving: 2450 physical core-years
RSA-250 matrix: 250 physical core-years

The computation involved tens of thousands of machines worldwide, and was completed in a few months.

News article. On the factoring challenges.

Posted on April 8, 2020 at 6:37 AM15 Comments

Cybersecurity During COVID-19

Three weeks ago (could it possibly be that long already?), I wrote about the increased risks of working remotely during the COVID-19 pandemic.

One, employees are working from their home networks and sometimes from their home computers. These systems are more likely to be out of date, unpatched, and unprotected. They are more vulnerable to attack simply because they are less secure.

Two, sensitive organizational data will likely migrate outside of the network. Employees working from home are going to save data on their own computers, where they aren’t protected by the organization’s security systems. This makes the data more likely to be hacked and stolen.

Three, employees are more likely to access their organizational networks insecurely. If the organization is lucky, they will have already set up a VPN for remote access. If not, they’re either trying to get one quickly or not bothering at all. Handing people VPN software to install and use with zero training is a recipe for security mistakes, but not using a VPN is even worse.

Four, employees are being asked to use new and unfamiliar tools like Zoom to replace face-to-face meetings. Again, these hastily set-up systems are likely to be insecure.

Five, the general chaos of “doing things differently” is an opening for attack. Tricks like business email compromise, where an employee gets a fake email from a senior executive asking him to transfer money to some account, will be more successful when the employee can’t walk down the hall to confirm the email’s validity — and when everyone is distracted and so many other things are being done differently.

NASA is reporting an increase in cyberattacks. From an agency memo:

A new wave of cyber-attacks is targeting Federal Agency Personnel, required to telework from home, during the Novel Coronavirus (COVID-19) outbreak. During the past few weeks, NASA’s Security Operations Center (SOC) mitigation tools have prevented success of these attempts. Here are some examples of what’s been observed in the past few days:

  • Doubling of email phishing attempts
  • Exponential increase in malware attacks on NASA systems
  • Double the number of mitigation-blocking of NASA systems trying to access malicious sites (often unknowingly) due to users accessing the Internet

Here’s another article that makes basically the same points I did:

But the rapid shift to remote working will inevitably create or exacerbate gaps in security. Employees using unfamiliar software will get settings wrong and leave themselves open to breaches. Staff forced to use their own ageing laptops from home will find their data to be less secure than those using modern equipment.

That’s a big problem because the security issues are not going away. For the last couple of months coronavirus-themed malware and phishing scams have been on the rise. Business email compromise scams — where crooks impersonate a CEO or other senior staff member and then try to trick workers into sending money to their accounts — could be made easier if staff primarily rely on email to communicate while at home.

EDITED TO ADD: This post has been translated into Portuguese.

EDITED TO ADD (4/13): A three-part series about home-office cybersecurity.

EDITED TO ADD: This post has been translated into Spanish.

Posted on April 7, 2020 at 10:00 AM45 Comments

Emotet Malware Causes Physical Damage

Microsoft is reporting that an Emotet malware infection shut down a network by causing computers to overheat and then crash.

The Emotet payload was delivered and executed on the systems of Fabrikam — a fake name Microsoft gave the victim in their case study — five days after the employee’s user credentials were exfiltrated to the attacker’s command and control (C&C) server.

Before this, the threat actors used the stolen credentials to deliver phishing emails to other Fabrikam employees, as well as to their external contacts, with more and more systems getting infected and downloading additional malware payloads.

The malware further spread through the network without raising any red flags by stealing admin account credentials authenticating itself on new systems, later used as stepping stones to compromise other devices.

Within 8 days since that first booby-trapped attachment was opened, Fabrikam’s entire network was brought to its knees despite the IT department’s efforts, with PCs overheating, freezing, and rebooting because of blue screens, and Internet connections slowing down to a crawl because of Emotet devouring all the bandwidth.

The infection mechanism was one employee opening a malicious attachment to a phishing email. I can’t find any information on what kind of attachment.

Posted on April 6, 2020 at 11:26 AM16 Comments

Friday Squid Blogging: On Squid Communication

They can communicate using bioluminescent flashes:

New research published this week in Proceedings of the National Academy of Sciences presents evidence for a previously unknown semantic-like ability in Humboldt squid. What’s more, these squid can enhance the visibility of their skin patterns by using their bodies as a kind of backlight, which may allow them to convey messages of surprising complexity, according to the new paper. Together, this could explain how Humboldt squid­ — and possibly other closely related squid­ — are able to facilitate group behaviors in light-restricted environments, such as evading predators, finding places to forage, signaling that it’s time to feed, and deciding who gets priority at the dinner table, among other things.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Read my blog posting guidelines here.

Posted on April 3, 2020 at 4:30 PM125 Comments

Security and Privacy Implications of Zoom

Over the past few weeks, Zoom’s use has exploded since it became the video conferencing platform of choice in today’s COVID-19 world. (My own university, Harvard, uses it for all of its classes. Boris Johnson had a cabinet meeting over Zoom.) Over that same period, the company has been exposed for having both lousy privacy and lousy security. My goal here is to summarize all of the problems and talk about solutions and workarounds.

In general, Zoom’s problems fall into three broad buckets: (1) bad privacy practices, (2) bad security practices, and (3) bad user configurations.

Privacy first: Zoom spies on its users for personal profit. It seems to have cleaned this up somewhat since everyone started paying attention, but it still does it.

The company collects a laundry list of data about you, including user name, physical address, email address, phone number, job information, Facebook profile information, computer or phone specs, IP address, and any other information you create or upload. And it uses all of this surveillance data for profit, against your interests.

Last month, Zoom’s privacy policy contained this bit:

Does Zoom sell Personal Data? Depends what you mean by “sell.” We do not allow marketing companies, or anyone else to access Personal Data in exchange for payment. Except as described above, we do not allow any third parties to access any Personal Data we collect in the course of providing services to users. We do not allow third parties to use any Personal Data obtained from us for their own purposes, unless it is with your consent (e.g. when you download an app from the Marketplace. So in our humble opinion, we don’t think most of our users would see us as selling their information, as that practice is commonly understood.

“Depends what you mean by ‘sell.'” “…most of our users would see us as selling…” “…as that practice is commonly understood.” That paragraph was carefully worded by lawyers to permit them to do pretty much whatever they want with your information while pretending otherwise. Do any of you who “download[ed] an app from the Marketplace” remember consenting to them giving your personal data to third parties? I don’t.

Doc Searls has been all over this, writing about the surprisingly large number of third-party trackers on the Zoom website and its poor privacy practices in general.

On March 29th, Zoom rewrote its privacy policy:

We do not sell your personal data. Whether you are a business or a school or an individual user, we do not sell your data.

[…]

We do not use data we obtain from your use of our services, including your meetings, for any advertising. We do use data we obtain from you when you visit our marketing websites, such as zoom.us and zoom.com. You have control over your own cookie settings when visiting our marketing websites.

There’s lots more. It’s better than it was, but Zoom still collects a huge amount of data about you. And note that it considers its home pages “marketing websites,” which means it’s still using third-party trackers and surveillance based advertising. (Honestly, Zoom, just stop doing it.)

Now security: Zoom’s security is at best sloppy, and malicious at worst. Motherboard reported that Zoom’s iPhone app was sending user data to Facebook, even if the user didn’t have a Facebook account. Zoom removed the feature, but its response should worry you about its sloppy coding practices in general:

“We originally implemented the ‘Login with Facebook’ feature using the Facebook SDK in order to provide our users with another convenient way to access our platform. However, we were recently made aware that the Facebook SDK was collecting unnecessary device data,” Zoom told Motherboard in a statement on Friday.

This isn’t the first time Zoom was sloppy with security. Last year, a researcher discovered that a vulnerability in the Mac Zoom client allowed any malicious website to enable the camera without permission. This seemed like a deliberate design choice: that Zoom designed its service to bypass browser security settings and remotely enable a user’s web camera without the user’s knowledge or consent. (EPIC filed an FTC complaint over this.) Zoom patched this vulnerability last year.

On 4/1, we learned that Zoom for Windows can be used to steal users’ Window credentials.

Attacks work by using the Zoom chat window to send targets a string of text that represents the network location on the Windows device they’re using. The Zoom app for Windows automatically converts these so-called universal naming convention strings — such as \attacker.example.com/C$ — into clickable links. In the event that targets click on those links on networks that aren’t fully locked down, Zoom will send the Windows usernames and the corresponding NTLM hashes to the address contained in the link.

On 4/2, we learned that Zoom secretly displayed data from people’s LinkedIn profiles, which allowed some meeting participants to snoop on each other. (Zoom has fixed this one.)

I’m sure lots more of these bad security decisions, sloppy coding mistakes, and random software vulnerabilities are coming.

But it gets worse. Zoom’s encryption is awful. First, the company claims that it offers end-to-end encryption, but it doesn’t. It only provides link encryption, which means everything is unencrypted on the company’s servers. From the Intercept:

In Zoom’s white paper, there is a list of “pre-meeting security capabilities” that are available to the meeting host that starts with “Enable an end-to-end (E2E) encrypted meeting.” Later in the white paper, it lists “Secure a meeting with E2E encryption” as an “in-meeting security capability” that’s available to meeting hosts. When a host starts a meeting with the “Require Encryption for 3rd Party Endpoints” setting enabled, participants see a green padlock that says, “Zoom is using an end to end encrypted connection” when they mouse over it.

But when reached for comment about whether video meetings are actually end-to-end encrypted, a Zoom spokesperson wrote, “Currently, it is not possible to enable E2E encryption for Zoom video meetings. Zoom video meetings use a combination of TCP and UDP. TCP connections are made using TLS and UDP connections are encrypted with AES using a key negotiated over a TLS connection.”

They’re also lying about the type of encryption. On 4/3, Citizen Lab reported

Zoom documentation claims that the app uses “AES-256” encryption for meetings where possible. However, we find that in each Zoom meeting, a single AES-128 key is used in ECB mode by all participants to encrypt and decrypt audio and video. The use of ECB mode is not recommended because patterns present in the plaintext are preserved during encryption.

The AES-128 keys, which we verified are sufficient to decrypt Zoom packets intercepted in Internet traffic, appear to be generated by Zoom servers, and in some cases, are delivered to participants in a Zoom meeting through servers in China, even when all meeting participants, and the Zoom subscriber’s company, are outside of China.

I’m okay with AES-128, but using ECB (electronic codebook) mode indicates that there is no one at the company who knows anything about cryptography.

And that China connection is worrisome. Citizen Lab again:

Zoom, a Silicon Valley-based company, appears to own three companies in China through which at least 700 employees are paid to develop Zoom’s software. This arrangement is ostensibly an effort at labor arbitrage: Zoom can avoid paying US wages while selling to US customers, thus increasing their profit margin. However, this arrangement may make Zoom responsive to pressure from Chinese authorities.

Or from Chinese programmers slipping backdoors into the code at the request of the government.

Finally, bad user configuration. Zoom has a lot of options. The defaults aren’t great, and if you don’t configure your meetings right you’re leaving yourself open to all sort of mischief.

Zoombombing” is the most visible problem. People are finding open Zoom meetings, classes, and events: joining them, and sharing their screens to broadcast offensive content — porn, mostly — to everyone. It’s awful if you’re the victim, and a consequence of allowing any participant to share their screen.

Even without screen sharing, people are logging in to random Zoom meetings and disrupting them. Turns out that Zoom didn’t make the meeting ID long enough to prevent someone from randomly trying them, looking for meetings. This isn’t new; Checkpoint Research reported this last summer. Instead of making the meeting IDs longer or more complicated — which it should have done — it enabled meeting passwords by default. Of course most of us don’t use passwords, and there are now automatic tools for finding Zoom meetings.

For help securing your Zoom sessions, Zoom has a good guide. Short summary: don’t share the meeting ID more than you have to, use a password in addition to a meeting ID, use the waiting room if you can, and pay attention to who has what permissions.

That’s what we know about Zoom’s privacy and security so far. Expect more revelations in the weeks and months to come. The New York Attorney General is investigating the company. Security researchers are combing through the software, looking for other things Zoom is doing and not telling anyone about. There are more stories waiting to be discovered.

Zoom is a security and privacy disaster, but until now had managed to avoid public accountability because it was relatively obscure. Now that it’s in the spotlight, it’s all coming out. (Their 4/1 response to all of this is here.) On 4/2, the company said it would freeze all feature development and focus on security and privacy. Let’s see if that’s anything more than a PR move.

In the meantime, you should either lock Zoom down as best you can, or — better yet — abandon the platform altogether. Jitsi is a distributed, free, and open-source alternative. Start your meeting here.

EDITED TO ADD: Fight for the Future is on this.

Steve Bellovin’s comments.

Meanwhile, lots of Zoom video recordings are available on the Internet. The article doesn’t have any useful details about how they got there:

Videos viewed by The Post included one-on-one therapy sessions; a training orientation for workers doing telehealth calls, which included people’s names and phone numbers; small-business meetings, which included private company financial statements; and elementary-school classes, in which children’s faces, voices and personal details were exposed.

Many of the videos include personally identifiable information and deeply intimate conversations, recorded in people’s homes. Other videos include nudity, such as one in which an aesthetician teaches students how to give a Brazilian wax.

[…]

Many of the videos can be found on unprotected chunks of Amazon storage space, known as buckets, which are widely used across the Web. Amazon buckets are locked down by default, but many users make the storage space publicly accessible either inadvertently or to share files with other people.

EDITED TO ADD (4/4): New York City has banned Zoom from its schools.

EDITED TO ADD: This post has been translated into Spanish.

Posted on April 3, 2020 at 10:10 AM81 Comments

Bug Bounty Programs Are Being Used to Buy Silence

Investigative report on how commercial bug-bounty programs like HackerOne, Bugcrowd, and SynAck are being used to silence researchers:

Used properly, bug bounty platforms connect security researchers with organizations wanting extra scrutiny. In exchange for reporting a security flaw, the researcher receives payment (a bounty) as a thank you for doing the right thing. However, CSO’s investigation shows that the bug bounty platforms have turned bug reporting and disclosure on its head, what multiple expert sources, including HackerOne’s former chief policy officer, Katie Moussouris, call a “perversion.”

[…]

Silence is the commodity the market appears to be demanding, and the bug bounty platforms have pivoted to sell what willing buyers want to pay for.

“Bug bounties are best when transparent and open. The more you try to close them down and place NDAs on them, the less effective they are, the more they become about marketing rather than security,” Robert Graham of Errata Security tells CSO.

Leitschuh, the Zoom bug finder, agrees. “This is part of the problem with the bug bounty platforms as they are right now. They aren’t holding companies to a 90-day disclosure deadline,” he says. “A lot of these programs are structured on this idea of non-disclosure. What I end up feeling like is that they are trying to buy researcher silence.”

The bug bounty platforms’ NDAs prohibit even mentioning the existence of a private bug bounty. Tweeting something like “Company X has a private bounty program over at Bugcrowd” would be enough to get a hacker kicked off their platform.

The carrot for researcher silence is the money — bounties can range from a few hundred to tens of thousands of dollars — but the stick to enforce silence is “safe harbor,” an organization’s public promise not to sue or criminally prosecute a security researcher attempting to report a bug in good faith.

Posted on April 3, 2020 at 6:21 AM19 Comments

Marriott Was Hacked — Again

Marriott announced another data breach, this one affecting 5.2 million people:

At this point, we believe that the following information may have been involved, although not all of this information was present for every guest involved:

  • Contact Details (e.g., name, mailing address, email address, and phone number)
  • Loyalty Account Information (e.g., account number and points balance, but not passwords)
  • Additional Personal Details (e.g., company, gender, and birthday day and month)
  • Partnerships and Affiliations (e.g., linked airline loyalty programs and numbers)
  • Preferences (e.g., stay/room preferences and language preference)

This isn’t nearly as bad as the 2014 Marriott breach — made public in 2018 — which was the work of the Chinese government. But it does call into question whether Marriott is taking security seriously at all. It would be nice if there were a government regulatory body that could investigate and hold the company accountable.

Posted on April 2, 2020 at 11:33 AM18 Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.