Attacking the Phishing Epidemic

As long as people can be tricked, there will always be phishing (or social engineering) on some level or another, but there’s a lot more that we can do with technology to reduce the effectiveness of phishing, and the number of people falling victim to common theft. Making phishing less effective ultimately increases the cost to the criminal, and reduces the total payoff. Few will argue that our existing authentication technologies are stuck in a time warp, with some websites still using standards that date back to the 1990s. Browser design hasn’t changed very much since the Netscape days either, so it’s no wonder many people are so easily fooled by website counterfeits.

You may have heard of a term called the line of death. This is used to describe the separation between the trusted components of a web browser (such as the address bar and toolbars) and the untrusted components of a browser, namely the browser window. Phishing is easy because this is a farce. We allow untrusted elements in the trusted windows (such as a favicon, which can display a fake lock icon), tolerate financial institutions that teach users to accept any variation of their domain, and use a tiny monochrome font that can make URLs easily mistakable, even if users were paying attention to them. Worse even, it’s the untrusted space that we’re telling users to conduct the trusted operations of authentication and credit card transactions – the untrusted website portion of the web browser!.

Our browsers are so awful today that the very best advice we can offer everyday people is to try and memorize all the domains their bank uses, and get a pair of glasses to look at the address bar. We’re teaching users to perform trusted transactions in a piece of software that has no clear demarcation of trust.

The authentication systems we use these days were designed to be able to conduct secure transactions with anyone online, not knowing who they are, but most users today know exactly who they’re doing business with; they do business with the same organizations over and over; yet to the average user, a URL or an SSL certificate with a slightly different name or fingerprint means nothing. The average user relies on the one thing we have no control over: What the content looks like.

I propose we flip this on its head.

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Confide: A Quick Look

My inbox has been lighting up with questions about Confide, after it was allegedly found to have been used by staffers at the White House. I wish I had all of the free time that reporters think I have (I’d be so happy, living life as a broke beach bum). I did spend a little bit of time, however reverse engineering the binary and doing a simple forensic examination of it. Here’s my “literature in a rush” version.

Note: When I first wrote this blog post, I apparently had run into some corruption or some other strangeness going on with the framework; I suspect one of the tools I normally use might have decrypted it for me, and done a shoddy job without even telling me, so I have decrypted it by hand dumping memory from a debugger, and have updated my findings accordingly.

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Protecting Your Data at a Border Crossing

With the current US administration pondering the possibility of forcing foreign travelers to give up their social media passwords at the border, a lot of recent and justifiable concern has been raised about data privacy. The first mistake you could make is presuming that such a policy won’t affect US citizens.  For decades, JTTFs (Joint Terrorism Task Forces) have engaged in intelligence sharing around the world, allowing foreign governments to spy on you on behalf of your home country, passing that information along through various databases. What few protections citizens have in their home countries end at the border, and when an ally spies on you, that data is usually fair game to share back to your home country. Think of it as a backdoor built into your constitutional rights. To underscore the significance of this, consider that the president signed an executive order just today stepping up efforts at fighting international crime, which will likely result in the strengthening of resources to a JTTFs to expand this practice of “spying on my brother’s brother for him”. With this, the president also counted the most common crimes – drugs, gangs, racketeering, etc – as matters of “national security”.

Once policies that require surrendering passwords (I’ll call them password policies from now on) are adopted, the obvious intelligence benefit will no doubt inspire other countries to establish reciprocity in order to leverage receiving better intelligence about their own citizens traveling abroad. It’s likely the US will inspire many countries, including oppressive nations, to institute the same password policies at the border. This will ultimately be used to skirt search and seizure laws by opening up your data to forensic collection. In other words, you don’t need Microsoft to service a warrant, nor will the soil your data sits on matter, because it will be a border agent connecting directly your account with special software throug the front door.

I am not a lawyer, and I can’t provide you with legal advice about your rights, or what you can do at a border crossing to protect yourself legally, but I can explain the technical implications of this, as well as provide some steps you can take to protect your data regardless of what country you’re entering. Disclaimer: You accept full responsibility and liability for taking any of this information and using it.

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Slides: Crafting macOS Root Kits

Here are the slides from my talk at Dartmouth College this week; this was a basic introduction / overview of the macOS kernel and how root kits often have fun with the kernel. There’s not much new here, but the deck might be a good introduction for anyone looking to get into develop security tools or conduct security research in macOS. Note: Root kits aren’t exploits; there’s no exploit code in this deck. Sorry!

Crafting macOS Root Kits

Resolving Kernel Symbols in a Post-ASLR macOS World

There are some 21,000 symbols in the macOS kernel, but all but around 3,500 are opaque even to kernel developers. The reasoning behind this was likely twofold: first, Apple is continually making changes and improvements in the kernel, and they probably don’t want kernel developers mucking around with unstable portions of the code. Secondly, kernel dev used to be the wild wild west, especially before you needed a special code signing cert to load a kext, and there were a lot of bad devs who wrote awful code making macOS completely unstable. Customers running such software probably blamed Apple for it, instead of the developer. Apple now has tighter control over who can write kernel code, but it doesn’t mean developers have gotten any better at it. Looking at some commercial products out there, there’s unsurprisingly still terrible code to do things in the kernel that should never be done.

So most of the kernel is opaque to kernel developers for good reason, and this has reduced the amount of rope they have to hang themselves with. For some doing really advanced work though (especially in security), the kernel can sometimes feel like a Fisher Price steering wheel because of this, and so many have found ways around privatized functions by resolving these symbols and using them anyway. After all, if you’re going to combat root kits, you have to act like a root kit in many ways, and if you’re going to combat ransomware, you have to dig your claws into many of the routines that ransomware would use – some of which are privatized.

Today, there are many awful implementations of both malware and anti-malware code out there that resolve these private kernel symbols. Many of them do idiotic things like open and read the kernel from a file, scan memory looking for magic headers, and other very non-portable techniques that risk destabilizing macOS even more. So I thought I’d take a look at one of the good examples that particularly stood out to me. Some years back, Nemo and Snare wrote some good in-memory symbol resolving code that walked the LC_SYMTAB without having to read the kernel from disk, scan memory, or do any other disgusting things, and did it in a portable way that worked on whatever new versions of macOS came out. 

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