Last Updated: 2012-02-20 16:46:34 UTC
by Pedro Bueno (Version: 1)
A lot of people ask me what kind of tools I use for malware research.
That's definitely a really broad question, because sometimes each malware may need a different approach. However, there are some simple tools that can help on a first approach and sometimes will give all the answers you need, without the need to go deeper on more complete debuggers and disassemblers as OllyDbg and IDA Pro, which by the way are two great tools!
For this diary I am not considering exploits, like pdf or java exploits, but just plain PE files ( EXE and DLLs).
As part of my "first look kit" I use the pescanner python script from Malware Analysis Cookbook, which the authors made available here .
This script can give you some valuable information about the PE file, like the PE Sections, Version information (if available), and compilation date. Because there are some known bad indicators, the script will also print out the [SUSPICIOUS] word when it finds one of those indicators, such as strange compilation date, and strange entropy values found on the PE Sections.
Once you are used to the analysis, a simple look on this will help you to identify possible malicious files. Since it was based on Ero Carrera's pefile python module, you can modify and add additional features if you think is necessary. One addition I did on mine was to show if the file contains an overlay. On a few situations you should see valid overlay in files, and it is very common to find parasitic virus including its code as an overlay on the PE file.
Another great tool that I use is called HIEW (Hacker's View) hex editor. It is a really complete "old-style" tool. I mean old style because it uses a DOS window, there is no GUI...:)
It has a lot of features, from a complete HEX editor, an ASCII view of the file, and a "Decode" view, where you are presented with a disassembler. It also contains several shortcuts with pre-defined functions, as to show you the basic PE information, the number of sections, the entry point address and much more.
It also allows you to go straight to section you want or jump to a specific address on the file, list the imports and exports and even edit the file.
It is a paid tool available here , but it contains a free version (6.50) which does not contain all features but can definitely give you a feel of it.
There was a open source product called Biew that had almost the same features of Hiew, but seems that it is not being updated since 2009.
Another tool that I've been checking lately is called HT Editor, that is a promissing project. It still doesnt have a lot of feaures but I like it. You may check it here
Pedro Bueno (pbueno /%%/ isc. sans. org)