Malware Analysis

Posts discussing malware analysis techniques.

There’s a theory that a thousand monkeys typing away at a thousand typewriters will eventually reproduce the works of Shakespeare. I got home one day to find a JavaScript downloader semi-randomly creating dynamic functions until one of them worked and downloaded some malware that I hadn’t seen before. Continue Reading

Previous posts in this series have demonstrated how, when used on a CryptoLocker variant, extracts the malicious PE file injected in to explorer.exe, and how it can also be used to analyse the injected PE file. This post demonstrates how can now be used to analyse our CryptoLocker variant’s network communications by dumping the cleartext traffic sent over its HTTPS connections.

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My automated unpacking script (which really needs a sensible name!) is a few years old now, so I was interested to see how it would go with some malware that was developed after it was. That is, I wanted to answer the question ‘is my script still useful?’. It turns out it is still useful, and this post is the first of a few posts that aim to demonstrate why. Continue Reading

… and without touching Perl I might add. So, someone has just handed you a collection of Microsoft Word documents that they believe are malicious and you’re keen to investigate them to see if you can get your hands on some more malware to analyse. Here is how you can analyse Microsoft Word documents in a Linux environment, without using Microsoft Word (and without using Perl). Continue Reading

I was just in the middle of doing a post on analysing a malware sample and I thought that I should start it off by documenting my setup. It then occurred to me that doing so was making my post somewhat longer, and since the setup would apply pretty much to all of my malware analysis work, I should document it separately. So here it is — my malware analysis setup. Continue Reading

It’s been about a year and a half since I wrote about a behavioural approach to automated unpacking, and I figured it was time to add some more functionality to This time, I’m going to look at malware decrypting/decompressing code from within itself, and process hollowing, and see if we can capture the decrypted/decompressed/newly written memory. Let’s spruce up a tad. Continue Reading

To analyse the cna12 MySQL attacks, I had to install MySQL Express Server as the attacks were prematurely exiting when connecting to Dionaea. Extracting the binary files from the libpcap files was annoying, so I decided to change Dionaea so that it would automatically extract the binary files used in the cna12 attacks. Continue Reading

Certain memory conditions have to be met before malware can unpack code and run it — the memory has to be writeable to unpack code to it, and executable to be able to execute it. The question is, can we use Win32 API calls to detect malware creating these conditions, and subsequently not only detect and identify unpacked code, but also find the original entry point? Continue Reading