Robert Graham

Author Archives: Robert Graham

About them Zoom vulns…

Today a couple vulnerabilities were announced in Zoom, the popular work-from-home conferencing app. Hackers can possibly exploit these to do evil things to you, such as steal your password. Because of the COVID-19, these vulns have hit the mainstream media. This means my non-techy friends and relatives have been asking about it. I thought I'd write up a blogpost answering their questions.

The short answer is that you don't need to worry about it. Unless you do bad things, like using the same password everywhere, it's unlikely to affect you. You should worry more about wearing pants on your Zoom video conferences in case you forget and stand up.



Now is a good time to remind people to stop using the same password everywhere and to visit https://haveibeenpwned.com to view all the accounts where they've had their password stolen. Using the same password everywhere is the #1 vulnerability the average person is exposed to, and is a possible problem here. For critical accounts (Windows login, bank, email), use a different password for each. (Sure, for accounts you don't care about, use the same password everywhere, I use 'Foobar1234'). Write these passwords down on paper and put that paper in Continue reading

Huawei backdoors explanation, explained

Today Huawei published a video explaining the concept of "backdoors" in telco equipment. Many are criticizing the video for being tone deaf. I don't understand this concept of "tone deafness". Instead, I want to explore the facts.


This video seems in response to last month's story about Huawei misusing law enforcement backdoors from the Wall Street Journal. All telco equipment has backdoors usable only by law enforcement, the accusation is that Huawei has a backdoor into this backdoor, so that Chinese intelligence can use it.

That story was bogus. Sure, Huawei is probably guilty of providing backdoor access to the Chinese government, but something is deeply flawed with this particular story.

We know something is wrong with the story because the U.S. officials cited are anonymous. We don't know who they are or what position they have in the government. If everything they said was true, they wouldn't insist on being anonymous, but would stand up Continue reading

A requirements spec for voting

In software development, we start with a "requirements specification" defining what the software is supposed to do. Voting machine security is often in the news, with suspicion the Russians are trying to subvert our elections. Would blockchain or mobile phone voting work? I don't know. These things have tradeoffs that may or may not work, depending upon what the requirements are. I haven't seen the requirements written down anywhere. So I thought I'd write some.


One requirement is that the results of an election must seem legitimate. That's why responsible candidates have a "concession speech" when they lose. When John McCain lost the election to Barack Obama, he started his speech with:
"My friends, we have come to the end of a long journey. The American people have spoken, and they have spoken clearly. A little while ago, I had the honor of calling Sen. Barack Obama — to congratulate him on being elected the next president of the country that we both love."
This was important. Many of his supporters were pointing out irregularities in various states, wanting to continue the fight. But there are always irregularities, or things that look like irregularities. In every election, if a Continue reading

There’s no evidence the Saudis hacked Jeff Bezos’s iPhone

There's no evidence the Saudis hacked Jeff Bezos's iPhone.

This is the conclusion of the all the independent experts who have reviewed the public report behind the U.N.'s accusations. That report failed to find evidence proving the theory, but instead simply found unknown things it couldn't explain, which it pretended was evidence.


This is a common flaw in such forensics reports. When there's evidence, it's usually found and reported. When there's no evidence, investigators keep looking. Todays devices are complex, so if you keep looking, you always find anomalies you can't explain. There's only two results from such investigations: proof of bad things or anomalies that suggest bad things. There's never any proof that no bad things exist (at least, not in my experience).

Bizarre and inexplicable behavior doesn't mean a hacker attack. Engineers trying to debug problems, and support technicians helping customers, find such behavior all the time. Pretty much every user of technology experiences this. Paranoid users often think there's a conspiracy against them when electronics behave strangely, but "behaving strangely" is perfectly normal.

When you start with the theory that hackers are involved, then you have an explanation for the all that's unexplainable. It's all Continue reading

How to decrypt WhatsApp end-to-end media files

At the center of the "Saudis hacked Bezos" story is a mysterious video file investigators couldn't decrypt, sent by Saudi Crown Prince MBS to Bezos via WhatsApp. In this blog post, I show how to decrypt it. Once decrypted, we'll either have a smoking gun proving the Saudi's guilt, or exoneration showing that nothing in the report implicated the Saudis. I show how everyone can replicate this on their own iPhones.

The steps are simple:
  • backup the phone to your computer (macOS or Windows), using one of many freely available tools, such as Apple's own iTunes app
  • extract the database containing WhatsApp messages from that backup, using one of many freely available tools, or just hunt for the specific file yourself
  • grab the .enc file and decryption key from that database, using one of many freely available SQL tools
  • decrypt the video, using a tool I just created on GitHub

End-to-end encrypted downloader

The FTI report says that within hours of receiving a suspicious video that Bezos's iPhone began behaving strangely. The report says:
...analysis revealed that the suspect video had been delivered via an encrypted downloader host on WhatsApp’s media server. Due to WhatsApp’s end-to-end encryption, the contents Continue reading

So that tweet was misunderstood

I'm currently experiencing the toxic hell that is a misunderstood tweet going viral. It's a property of the social media. The more they can deliberately misunderstand you, the more they can justify the toxicity of their response. Unfortunately, I had to delete it in order to stop all the toxic crud and threats of violence.

The context is how politicians distort everything. It's like whenever they talk about sea level rise, it's always about some city like Miami or New Orleans that is sinking into the ocean already, even without global warming's help. Pointing this out isn't a denial of global warming, it's pointing out how we can't talk about the issue without exaggeration. Mankind's carbon emissions are indeed causing sea level to rise, but we should be talking about how this affects average cities, not dramatizing the issue with the worst cases.

The same it true of health care. It's a flawed system that needs change. But we don't discuss the people making the best of all bad choices. Instead, we cherry pick those who made the worst possible choice, and then blame the entire bad outcome on the system.

My tweet is in response to this Elizabeth Warren Continue reading

This is finally the year of the ARM server

"RISC" was an important architecture from the 1980s when CPUs had fewer than 100,000 transistors. By simplifying the instruction set, they free up transistors for more registers and better pipelining. It meant executing more instructions, but more than making up for this by executing them faster.

But once CPUs exceed a million transistors around 1995, they moved to Out-of-Order, superscalar architectures. OoO replaces RISC by decoupling the front-end instruction-set with the back-end execution. A "reduced instruction set" no longer matters, the backend architecture differs little between Intel and competing RISC chips like ARM. Yet people have remained fixated on instruction set. The reason is simply politics. Intel has been the dominant instruction set for the computers we use on servers, desktops, and laptops. Many instinctively resist whoever dominates. In addition, colleges indoctrinate students on the superiority of RISC. Much college computer science instruction is decades out of date.

For 10 years, the ignorant press has been championing the cause of ARM's RISC processors in servers. The refrain has always been that RISC has some inherent power efficiency advantage, and that ARM processors with natural power efficiency from the mobile world will be more power efficient for the data center.

None Continue reading

CrowdStrike-Ukraine Explained

Trump's conversation with the President of Ukraine mentions "CrowdStrike". I thought I'd explain this.


What was said?

This is the text from the conversation covered in this
“I would like you to find out what happened with this whole situation with Ukraine, they say Crowdstrike... I guess you have one of your wealthy people... The server, they say Ukraine has it.”
Personally, I occasionally interrupt myself while speaking, so I'm not sure I'd criticize Trump here for his incoherence. But at the same time, we aren't quite sure what was meant. It's only meaningful in the greater context. Trump has talked before about CrowdStrike's investigation being wrong, a rich Ukrainian owning CrowdStrike, and a "server". He's talked a lot about these topics before.


Who is CrowdStrike?

They are a cybersecurity firm that, among other things, investigates hacker attacks. If you've been hacked by a nation state, then CrowdStrike is the sort of firm you'd hire to come and investigate what happened, and help prevent it from happening again.


Why is CrowdStrike mentioned?

Because they were the lead investigators in the DNC hack who came to the conclusion that Russia was responsible. The pro-Trump crowd believes this conclusion is Continue reading

Thread on the OSI model is a lie

I had a Twitter thread on the OSI model. Below it's compiled into one blogpost
Yea, I've got 3 hours to kill here in this airport lounge waiting for the next leg of my flight, so let's discuss the "OSI Model". There's no such thing. What they taught you is a lie, and they knew it was a lie, and they didn't care, because they are jerks.
You know what REALLY happened when the kid pointed out the king was wearing no clothes? The kid was punished. Nobody cared. And the king went on wearing the same thing, which everyone agreed was made from the finest of cloth.
The OSI Model was created by international standards organization for an alternative internet that was too complicated to ever work, and which never worked, and which never came to pass.
Sure, when they created the OSI Model, the Internet layered model already existed, so they made sure to include today's Internet as part of their model. But the focus and intent of the OSI's efforts was on dumb networking concepts that worked differently from the Internet.
OSI wanted a "connection-oriented network layer", one that worked like the telephone system, where every switch Continue reading

Thread on network input parsers

This blogpost contains a long Twitter thread on input parsers. I thought I'd copy the thread here as a blogpost.
I am spending far too long on this chapter on "parsers". It's this huge gaping hole in Computer Science where academics don't realize it's a thing. It's like physics missing one of Newton's laws, or medicine ignoring broken bones, or chemistry ignoring fluorine.
The problem is that without existing templates of how "parsing" should be taught, it's really hard coming up with a structure for describing it from scratch.
"Langsec" has the best model, but at the same time, it's a bit abstract ("input is a language that drives computation"), so I want to ease into it with practical examples for programmers.
Among the needed steps is to stamp out everything you were taught in C/C++ about pointer-arithmetic and overlaying internal packed structures onto external data. Big-endian vs. little-endian isn't confusing -- it's only made confusing because you were taught it wrongly.
Hmmm. I already see a problem with these tweets. People assume I mean "parsing programming languages", like in the Dragon book. Instead, I mean parsing all input, such as IP headers, PDF files, X.509 certificates, and so Continue reading

Hacker Jeopardy, Wrong Answers Only Edition

Among the evening entertainment at DEF CON is "Hacker Jeopardy", like the TV show Jeopardy, but with hacking tech/culture questions. In today's blog post, we are going to play the "Wrong Answers Only" version, in which I die upon the hill defending the wrong answer.

The problem posed is this:
YOU'LL LIKELY SHAKE YOUR HEAD WHEN YOU SEE TELNET AVAILABLE, NORMALLY SEEN ON THIS PORT
Apparently, people gave 21, 22, and 25 as the responses. The correct response, according to RFC assignments of well-known ports, is 23.

A good wrong answer is this one, port 25, where the Morris Worm spread via port 25 (SMTP) via the DEBUG command.

But the real correct response is port 21. The problem posed wasn't about which port was assigned to Telnet (port 23), but what you normally see these days.

Port 21 is assigned to FTP, the file transfer protocol. A little known fact about FTP is that it uses Telnet for it's command-channel on port 21. In other words, FTP isn't a text-based protocol like SMTP, HTTP, POP3, and so on. Instead, Continue reading

Securing devices for DEFCON

There's been much debate whether you should get burner devices for hacking conventions like DEF CON (phones or laptops). A better discussion would be to list those things you should do to secure yourself before going, just in case.

These are the things I worry about:
  • backup before you go
  • update before you go
  • correctly locking your devices with full disk encryption
  • correctly configuring WiFi
  • Bluetooth devices
  • Mobile phone vs. Stingrays
  • USB
Backup

Traveling means a higher chance of losing your device. In my review of crime statistics, theft seems less of a threat than whatever city you are coming from. My guess is that while thieves may want to target tourists, the police want to even more the target gangs of thieves, to protect the cash cow that is the tourist industry. But you are still more likely to accidentally leave a phone in a taxi or have your laptop crushed in the overhead bin. If you haven't recently backed up your device, now would be an extra useful time to do this.

Anything I want backed up on my laptop is already in Microsoft's OneDrive, so I don't pay attention to this. However, I have a Continue reading

Why we fight for crypto

This last week, the Attorney General William Barr called for crypto backdoors. His speech is a fair summary of law-enforcement's side of the argument. In this post, I'm going to address many of his arguments.

The tl;dr version of this blog post is this:

  • Their claims of mounting crime are unsubstantiated, based on emotional anecdotes rather than statistics. We live in a Golden Age of Surveillance where, if any balancing is to be done in the privacy vs. security tradeoff, it should be in favor of more privacy.
  • But we aren't talking about tradeoff with privacy, but other rights. In particular, it's every much as important to protect the rights of political dissidents to keep some communications private (encryption) as it is to allow them to make other communications public (free speech). In addition, there is no solution to their "going dark" problem that doesn't restrict the freedom to run arbitrary software of the user's choice on their computers/phones.
  • Thirdly, there is the problem of technical feasibility. We don't know how to make backdoors available for law enforcement access that doesn't enormously reduce security for users.


Balance

The crux of his argument is balancing civil rights vs. safety, also described Continue reading

Censorship vs. the memes

The most annoying thing in any conversation is when people drop a meme bomb, some simple concept they've heard elsewhere in a nice package that they really haven't thought through, which takes time and nuance to rebut. These memes are often bankrupt of any meaning.

When discussing censorship, which is wildly popular these days, people keep repeating these same memes to justify it:
  • you can't yell fire in a crowded movie theater
  • but this speech is harmful
  • Karl Popper's Paradox of Tolerance
  • censorship/free-speech don't apply to private organizations
  • Twitter blocks and free speech
This post takes some time to discuss these memes, so I can refer back to it later, instead of repeating the argument every time some new person repeats the same old meme.


You can't yell fire in a crowded movie theater

This phrase was first used in the Supreme Court decision Schenck v. United States to justify outlawing protests against the draft. Unless you also believe the government can jail you for protesting the draft, then the phrase is bankrupt of all meaning.

In other words, how can it be used to justify the thing you are trying to censor and yet be an invalid justification for Continue reading

Some Raspberry Pi compatible computers

I noticed this spreadsheet over at r/raspberry_pi reddit. I thought I'd write up some additional notes.

https://docs.google.com/spreadsheets/d/1jWMaK-26EEAKMhmp6SLhjScWW2WKH4eKD-93hjpmm_s/edit#gid=0


Consider the Upboard, an x86 computer in the Raspberry Pi form factor for $99. When you include storage, power supplies, heatsinks, cases, and so on, it's actually pretty competitive. It's not ARM, so many things built for the Raspberry Pi won't necessarily work. But on the other hand, most of the software built for the Raspberry Pi was originally developed for x86 anyway, so sometimes it'll work better.

Consider the quasi-RPi boards that support the same GPIO headers, but in a form factor that's not the same as a RPi. A good example would be the ODroid-N2. These aren't listed in the above spreadsheet, but there's a tone of them. There's only two Nano Pi's listed in the spreadsheet having the same form factor as the RPi, but there's around 20 different actual boards with all sorts of different form factors and capabilities.

Consider the heatsink, which can make a big difference in the performance and stability of the board. You can put a small heatsink on any board, but you really need larger heatsinks and possibly fans. Some boards, Continue reading

Your threat model is wrong

Several subjects have come up with the past week that all come down to the same thing: your threat model is wrong. Instead of addressing the the threat that exists, you've morphed the threat into something else that you'd rather deal with, or which is easier to understand.


Phishing

An example is this question that misunderstands the threat of "phishing":



The (wrong) threat model is here is that phishing is an email that smart users with training can identify and avoid. This isn't true.

Good phishing messages are indistinguishable from legitimate messages. Said another way, a lot of legitimate messages are in fact phishing messages, such as when HR sends out a message saying "log into this website with your organization username/password".

Almost One Million Vulnerable to BlueKeep Vuln (CVE-2019-0708)

Microsoft announced a vulnerability in it's "Remote Desktop" product that can lead to robust, wormable exploits. I scanned the Internet to assess the danger. I find nearly 1-million devices on the public Internet that are vulnerable to the bug. That means when the worm hits, it'll likely compromise those million devices. This will likely lead to an event as damaging as WannaCry and notPetya from 2017 -- potentially worse, as hackers have since honed their skills exploiting these things for ransomware and other nastiness.

To scan the Internet, I started with masscan, my Internet-scale port scanner, looking for port 3389, the one used by Remote Desktop. This takes a couple hours, and lists all the devices running Remote Desktop -- in theory.

This returned 7,629,102 results (over 7-million). However, there is a lot of junk out there that'll respond on this port. Only about half are actually Remote Desktop.

Masscan only finds the open ports, but is not complex enough to check for the vulnerability. Remote Desktop is a complicated protocol. A project was posted that could connect to an address and test it, to see if it was patched or vulnerable. I took that project and optimized it a Continue reading

A lesson in journalism vs. cybersecurity

A recent NYTimes article blaming the NSA for a ransomware attack on Baltimore is typical bad journalism. It's an op-ed masquerading as a news article. It cites many to support the conclusion the NSA is to be blamed, but only a single quote, from the NSA director, from the opposing side. Yet many experts oppose this conclusion, such as @dave_maynor, @beauwoods, @daveaitel, @riskybusiness, @shpantzer, @todb, @hrbrmstr , ... It's not as if these people are hard to find, it's that the story's authors didn't look.


The main reason experts disagree is that the NSA's Eternalblue isn't actually responsible for most ransomware infections. It's almost never used to start the initial infection -- that's almost always phishing or website vulns. Once inside, it's almost never used to spread laterally -- that's almost always done with windows networking and stolen credentials. Yes, ransomware increasingly includes Eternalblue as part of their arsenal of attacks, but this doesn't mean Eternalblue is responsible for ransomware.

The NYTimes story takes extraordinary effort to jump around this fact, deliberately misleading the reader to conflate one with the other. A good example is this paragraph:


That link is a warning from last July about the "Emotet" ransomware and makes Continue reading

Programming languages infosec professionals should learn

Code is an essential skill of the infosec professional, but there are so many languages to choose from. What language should you learn? As a heavy coder, I thought I'd answer that question, or at least give some perspective.

The tl;dr is JavaScript. Whatever other language you learn, you'll also need to learn JavaScript. It's the language of browsers, Word macros, JSON, NodeJS server side, scripting on the command-line, and Electron apps. You'll also need to a bit of bash and/or PowerShell scripting skills, or SQL for queries. Other languages are important as well, Python is very popular for example. Actively avoid C++ and PHP as they are obsolete.

Also tl;dr: whatever language you decide to learn, also learn how to use an IDE with visual debugging, rather than just a text editor. That problems means Visual Code from Microsoft.

Let's talk in general terms. Here are some types of languages.

  • Unavoidable. As mentioned above, familiarity with JavaScript, bash/Powershell, and SQL are unavoidable. If you are avoiding them, you are doing something wrong.
  • Small scripts. You need to learn at least one language for writing quick-and-dirty command-line scripts to automate tasks or process data. As a tool using animal, this Continue reading

Was it a Chinese spy or confused tourist?

Politico has an article from a former spy analyzing whether the "spy" they caught at Mar-a-lago (Trump's Florida vacation spot) was actually a "spy". I thought I'd add to it from a technical perspective about her malware, USB drives, phones, cash, and so on.

The part that has gotten the most press is that she had a USB drive with evil malware. We've belittled the Secret Service agents who infected themselves, and we've used this as the most important reason to suspect she was a spy.

But it's nonsense.

It could be something significant, but we can't know that based on the details that have been reported. What the Secret Service reported was that it "started installing software". That's a symptom of a USB device installing drivers, not malware. Common USB devices, such as WiFi adapters, Bluetooth adapters, microSD readers, and 2FA keys look identical to flash drives, and when inserted into a computer, cause Windows to install drivers.

Visual "installing files" is not a symptom of malware. When malware does its job right, there are no symptoms. It installs invisibly in the background. Thats the entire point of malware, that you don't know it's there. It's not to say Continue reading
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