There is an excellent introductory whitepaper on SEARCH.org called How to Capture a MySpace Page for Investigative Purposes that I think should be basic reading for every Internet investigator. It will serve as a baseline for capturing evidence from any on-line investigation.
The whitepaper recommends using screen capture video recording software called Camtasia by Techsmith. I have limited experience with this particular software but have used other freeware and video capture services for similar purposes. I have used Techsmith`s Snagit product before and I have had good luck with it.
The whitepaper also suggests using Video Downloadhelper, a Firefox extention to capture videos. I’ve used this app for a long time and like it a lot; however, some people prefer commercial products and there are those which are not free but are quite reasonalby priced, such as SWF Toolbox and RealPlayer Plus. I particularly like the SWF Toolbox for the additional functionality, but Realplayer Plus is a well known brand and some people take comfort in that.
There are a couple of key points to take from the white paper which I think are worth highlighting:
- Make sure you record the audio files separately
- Make sure you capture the video files separately
- Make sure you capture the HTML code by either opening up the source code through “View Source” or by saving a copy of the web page. The white paper suggests that it is important to do because the HTML would show any hidden trackers or code that might not show up on the rendered web page; and because a person who is competent in HTML could recreate the page with the appropriate tools (a variation the old “a competent person with the same information would reach the same conclusions argument”).
I also believe however, that it is important to capture the HTML for a variety of other reasons. Not least of which is to find out the original source of referenced material. Embedded keywords in headers can also help demonstrate mens rea. I put these here to attract a certain type of traffic from search engines (i.e. search engine optimization, a kind of marketing), therefore I knew what I was doing when I posted these fake identity cards for sale on line……and so the argument goes.
The white paper is aimed at MySpace, but given the fact that social media is so prolific, and because just about every kind of webpage can contains just about every kind of content the points could be applicable to most forensic Internet investigations.
There are a few areas that the white paper could have addressed, although to some they may be obvious. First, the investigators notes should reflect what he or she is doing and how they arrived at where they did. This includes things like the search terms they used, when they conducted the research, etc. A Google search on Monday may not provide the same results on Friday, but at least it should be clear to observers that when the search was done these are the results which were provided.
Second, a video is nice, and you can certainly take stills from a video to put them in your report, but I also like to produce pdfs of webpages. These work well in written reports.
Third, there is the issue of non-repudiation for the evidence you collected. Creating a checksum all of the information you obtain and then burning everything to a DVD and closing the session is a good idea. I`m using a DVD-R as an example, but I`m technology neutral. An encrypted flash drive or SD card or whatever else you prefer would also work.
Some of these principles are discussed further in Vere Software whitepaper “Collecting Legally Defensible Online Evidence.” I`ve blogged about this before and I think it is also good, basic reading.
Last but not least, the speed at which you capture information is important. You don’t want to go through a lot of effort to record things and then end up producing a video that is blurred. Editing can clean up the video a little bit but it is a huge time consumer and you cannot over edit lest your video be rejected as investigators should be aware of this constraint and move slowly if they are going to capture their sessions by a screen capture.
I’d also recommend that readers check out the other great publicly available whitepaper that is on the Search.org website for doing Internet investigations called “Setting up an Online Investigative Computer: Hardware, Connectivity and Software Recomendations”. It was written in 2004 so some of the specifications are a little old, but the principles are still relevant.
In my view the technology is going to keep evolving and because of this we must stay grounded in the basics. Improving searching by using semantic search techniques that understand natural language is fine, but it is still searching and we must be able to explain how we arrived at the results we did. Social networking sites, virtual worlds and so on are all interesting and important; and evidence will exist in these places, but just like the old school chatroom, they are all just tools for communicating in different ways.
Ours is to know the principles and evolve the processes for the new technologies.