Wednesday, July 10, 2013

Daily Blog #17: Milestones 11 and 12 detailed

Howdy Reader,
                 It's day 2 of the DFIR Summit and after winning the award for "4:Cast award for Best Forensic Article of the Year" (woo!) it's time to write another blog! Today we will be continuing the milestone series which should be done this week. Yesterday we talked about milestones 9 and 10 and today we continue to Milestones 11 and 12, coming ever closer to the end of my defined career progression.

Milestone 11 - You've realized that to optimize your workflow you need to learn some basic programming.
   
    Up to this point none of the milestones presented required anything but your knowledge of tools, artifacts, operating systems and file systems to progress. At this point though we have reached the level where you will  have to cross the gap from user to developer. For people who have never programmed before this seems like an insurmountable task, my advice to you is to put your goals into perspective and reduce the scope of the problem you are trying to solve.

    Why do you need to learn how to program? This is usually the most common question I'm asked when I bring up this point and argue its necessity. This is my answer; if you want keep growing as an examiner and become more efficient in your process while reducing frustration you will have to learn how to automate your tool execution. This will start being as simple as batch scripts that kick off a series of one off tools in your process (prefetch, reg ripper, journal parser, lnk parser, etc...), saving you time and allowing more blog reading while things run. Once you've achieved the batch script automation you'll start thinking about how to improve it by adding some basic decision trees allowing the batch script to run additional processes depending how a previous artifact exited or what other files exist in a directory. Once you've made this first progression from "series of commands executed in order", to "commands executed and some program logic decides what will happen next" you've made an important step into becoming a developer.
 
    It’s that first step that will, over time, drive you towards bridging the gap from scripting to programming as you continue to explore new things you can add to your scripts that will make your life easier. That is what learning to program is about, making your life easier by letting the programming logic you wrote once to perform the same repetitive actions and simple analysis for you one hundred times over. Once you reach the limit of what batch scripting will do for you it's time to expand into more functional programming languages. You might choose to go to a scripting language like perl (clearly the right choice), autoit script (Hi Joakim) or python (also cool) while others will make the jump to C++/C#/Java, etc... There is no wrong answer here on where you start and where you progress to - as long as your transition does not overwhelm you. My advice would be that if the structures necessary to write your program are more complicated than your program code then you might want to take a step back to a simpler language until you need the functionality provided by a more advanced language. 
    The purpose of this milestone is not to make you a developer full time. It is to make you a better examiner by automating parts of your analysis/processing/reporting that don't require you to apply the knowledge you have to make a decision. Instead of just doing repetitive tasks that keep you confined to your keyboard you will be able to switch focus to other tasks and become more productive and informed!
 
Milestone 12 - You've found enough deficiencies in the tools you use that you begin to write your own.
 
 
    At this point you've developed enough automation code to become a decent DFIR developer. You start reading the code in some of the open source tools you use to try to better understand what and how they do what they do. You think about submitting changes to fix problems you find in your work. Over time you may find that if the tool would only work by doing X instead of Y or reported in Z format it would be so much more useful to you, and instead of trying to rewrite someone else's tool you write one from scratch yourself to learn more. 
 
    What language you write your tool in does not matter, what matters is that you have found a real world problem to solve with your programming abilities that will propel you forward. Nothing helps you become a better developer than having a problem you really care about to solve. The more of these problems you find to solve the better a developer you will become. Your program's needs will continue to define your choice of language and libraries and there is so much example code and data structures out there to help you! It's not important if what you are writing has been solved 100 times before by a multitude of tools, what matters is that you successfully create your own version of that tool which solves your unique need.
 
    This is a huge step in your progression as you begin to recognize unknown artifacts in your re-creation testing and analysis and can start doing your own analysis to find them, which is covered in the next milestone!

    Tomorrow we finish the milestones series and see which topic from my list looks more appealing to write about.