RE: Encase and data recovery

From: Jason Frey (Jason.Freyat_private)
Date: Thu Mar 21 2002 - 09:03:51 PST

  • Next message: Paul Sanderson: "RE: Encase and data recovery"

    What about a product like the ImageMasster Solo2
    http://www.ics-iq.com/show_item_186.cfm?
    
    Of course, it still has an OS - it's basically a scaled down computer for
    the purpose of providing the task of copying.
    
    -----Original Message-----
    From: Fergus Cameron [mailto:tofergusat_private] 
    Sent: Wednesday, March 20, 2002 2:43 PM
    To: forensicsat_private
    Subject: Re: Encase and data recovery
    
    
    not sure this is really realisitic - for example you say you don't want an
    OS but you will need some form of 'Operating System'.  this is further
    complicated by the operation of copying sectors to sectors - there are a
    large number of drivers needed in that application - e.g. SCSI, ATA, etc not
    to mention a fairly difficult mapping, i mean without _identical_ disks how
    can you map 1 sector to another & at what level do you do it ?
    
    the idea is nice but i think the application may be far more complicated
    than it appears & certainly more than a few KB of code.
    
    On 19.03-10:28, Michael D. Barwise, BSc, IEng, MIIE, MBCS wrote:
    > Sorry to butt in- hope it's OK.
    > 
    > For this very reason (uncertainty of image accuracy), I have been
    > lobbying for ages for a dedicated imaging system which does not rely 
    > on an *operating system* or *architecture*. It's a ridiculously 
    > simple problem to solve (probably a few kB of code and a couple of 
    > interface cards).
    > 
    > On 25th Jun 2001 I sent this to the forensics digest, and I still
    > believe it's the right answer.
    > ------------------------
    > My ideal disk copier would be a very basic PC, probably one of those
    > compact industrial single-board ones, with a truly blank target disk 
    > and a spare port, running nothing except a custom-written native 
    > application which does nothing except read literal sectors from one 
    > hard disk to another (no OS). This application would be booted from 
    > floppy disk to start the copy process. The required code, if written 
    > in assembler, would be so small that it *could* be verified and 
    > certified by anyone competent to read the source code.
    > --------------------------
    > The code could alternatively be ROM-based.
    > 
    > So a dedicated tool that does just this job and has no other
    > function, which is simple enough to explain to the non-technical 
    > would solve this once and for all.
    > 
    > Michael D. Barwise, BSc, IEng, MIIE, MBCS
    > Computer Security Awareness
    > tel +44 (0)1442 266534 http://www.ComputerSecurityAwareness.com
    > 
    > Addressing the Human Equation in Information Security
    > 
    > ---------------------
    > message from Matt Pepe
    > > Just a couple of points to note about this problem. First, the issue 
    > > of using EnCase as an imaging solution. Since the "evidence" file 
    > > created (the .enN files) is not a true image, searches against it 
    > > can not be relied upon as being complete or accurate. You are forced 
    > > to use EnCase or restore the image, where other issues come into 
    > > play.  Especially if you happen to be working on a unix filesystem. 
    > > This is true of any proprietary imaging file format. Luckly, 
    > > Guidance has finally incorporated the ability to load in raw image 
    > > files ("dd", for instance).  Most forensics *labs* stay away from 
    > > using EnCase as an imaging solution.  On the analysis side, it's 
    > > great though.
    > > 
    > > <opinion tag>
    > > I vote we lobby Guidance for a tool that can convert their 
    > > proprietary file to a raw image. I have this funny feeling that if 
    > > they don't offer it soon, other forensic processing suites may have 
    > > the upper hand. </opinion
    > > tag>
    > > 
    > > The second point is that Rob is entirely correct. If you have any 
    > > suspicion that your results are not correct or complete, attempt to 
    > > perform the operation with a different set of tools. Do not believe 
    > > marketing material that states that collections of GNU or older (but
    > > reliable) DOS command line tools are not defensible in court. As 
    > > long as you are familiar with the tools, aware of their 
    > > shortcomings, and that the tools are acceptable (history of use, 
    > > widely accepted by other experts) in this field,  you should have 
    > > few problems.
    > > 
    > > One question though, Rob. Can you get the Unix port of these tools 
    > > to run on a sterilized version of DOS?  If not, the example you gave 
    > > may have just modified your evidence (copy), given your DOS prompt 
    > > and the fact that you are pointing to a physical device that we can 
    > > only assume is a restored image. I'm sure that you could, but it 
    > > would take a CD, or about 12 floppies to load the RAM disk with the 
    > > libraries.  I'm getting flashbacks to the 80's when my system didn't 
    > > have a hard drive.. :)
    > > 
    > > -- Matt
    > > 
    > > Quoting "Lee, Robert T." <ROBERT.T.LEE-2at_private>:
    > > 
    > > > Brandon,
    > > > 
    > > > Another option may be to compare the results from your Encase 
    > > > search and then run another search using the Unix port of 
    > > > "cat","strings", and "grep" on that filesystem and see if it 
    > > > produces any hits.
    > > > 
    > > > Example:
    > > > 
    > > > C:\>cat \\.\PhysicalDrive0 | strings | grep test
    > > > 
    > > > Or if you have multiple strings put them in a file and run
    > > > 
    > > > C:\>cat \\.\PhysicalDrive0 | strings | fgrep -f file-with-patterns
    > > > 
    > > > Or if you do not have the ports of these tools, mount the drive on 
    > > > your favorite Linux flavor or choice and run the same test.
    > > > 
    > > > Just a thought...  I would be interested to see if that produces 
    > > > the hits you are looking for.
    > > > 
    > > > --Rob
    > > > 
    > > 
    > > -----------------------------------------------------------------
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    > 
    > 
    > Michael D. Barwise, BSc, IEng, MIIE, MBCS
    > Computer Security Awareness
    > tel +44 (0)1442 266534 http://www.ComputerSecurityAwareness.com
    > 
    > Addressing the Human Equation in Information Security
    > 
    > -----------------------------------------------------------------
    > This list is provided by the SecurityFocus ARIS analyzer service. For 
    > more information on this free incident handling, management and 
    > tracking system please see: http://aris.securityfocus.com
    
    -- 
     Fergus Cameron                 Tel: +447779236010
                                    Fax: +447980681864
    
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