If you’re looking to get the Dragon Ball Z logo embroidered on something, they often charge a lot of money to convert the logo to the format that embroidery machines understand. Here’s a version I created in the Brother PES format, as well as in the native format I created it in (EmbroideryWare STICH). [Brother PES] [EmbroideryWare STICH]

If you’re looking to get the PowerShell logo embroidered on something, they often charge a lot of money to convert the logo to the format that embroidery machines understand. Here’s a version I created in the Brother PES format, as well as in the native format I created it in (EmbroideryWare STICH). [Brother PES] [EmbroideryWare STICH]

Background In the web application world – especially single-page applications – smooth and fluid interaction is key. For many years, these applications have been doing a pretty good job of getting this fluid interaction though AJAX techniques and browser support for XMLHttpRequest. One issue, however, is that XMLHttpRequest requires that all of your communication go through an text-based HTTP protocol. Another issue is that XMLHttpRequest doesn’t let a server initiate communication back to connected clients.

In 2003, Crosby and Wallach wrote an excellent paper demonstrating a new form of Denial of Service vulnerability against applications by abusing algorithmic complexity in the data structures that they depend on. For example, some data structures operate quite efficiently when given everyday input, but the performance degrades precipitously in certain edge cases. If an application provides user-controlled data to one of these data structures, attackers can intentionally provide this worst case form of input to generate a Denial of Service attack against the application.

After posting Extracting Activity History from PowerShell Process Dumps, I got an interesting follow up question: “Is it possible to extract the content of scripts (from disk) that were executed, even if those files were not captured?” The answer is “Yes”, but it’s also complicated. And to make it even more complicated, we’re going to go down a path showing how to do some of this detective work from scratch. This is going to require a lot of WinDbg automation, so for a first step, install the WinDbg module.

Imagine that you’re investigating the compromise of a system. The system doesn’t have PowerShell Logging enabled, but you did capture a process dump while activity was happening. This memory dump is forensic gold, and the managed code debugging extension for WinDbg (“SOS” – Son of Strike) gives you all the tools you need to mine it. After using File | Open Crash Dump, this is what you see: From there, load the SOS extension, fix symbols, and reload:

After it’s done indexing your data, Scour is blazingly fast at local content searches – far faster than Select-String, grep, or anything else that rips through files when you search. It accomplishes this through the power of the popular Lucene search engine. Similar to the way that publishers have made searching physical books fast, Lucene must first create an index of your content before you can search it. So while Scour was incredibly fast at searching content, the indexing process took much longer than I wanted it to.

If you have a large collection of documents (source code or text files), searching them with PowerShell or your favourite code editor can feel like it takes forever. Scour is a PowerShell module that surfaces the Apache Lucene project that can help.

So you’re interested in submitting a talk for a security conference? Awesome! Above all else, what keeps our industry moving forward is the free and open sharing of information. Submitting a talk can be a scary experience, and the process for how talks are evaluated can feel mysterious. So what’s the best way to create a good security conference CFP submission? It’s perhaps best to consider the questions that the review board will ask themselves as they review the submissions:

Mandiant recently posted some research about an attack leveraging the NetSupport Remote Access tool. The first stage of this attack uses a lot of obfuscation tricks to try to make reverse engineering more difficult. David Ledbetter and I were chatting about some of the lengths the malware authors went through to obfuscate the content. One of the major sources of complication is a complicated, iterative XOR: (Image credit Fake Software Update Abuses NetSupport Remote Access Tool | Mandiant)