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dd & dcfldd error message

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erowe
(@erowe)
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Joined: 18 years ago
Posts: 144
Topic starter  

I've been having a few problems doing memory dumps with dd and dcfldd on an XP Pro workstation, and I was wondering if anyone might be able to give me a bit of insight as to what I might be doing wrong.

When I open a command prompt and type in any variation on the following (with both dd and dcfldd - as well as with conv=sync,noerror and other options)

dcfldd if=\\.\PhysicalMemory of=dump.dd

I get the following error message

dcfldd\\.\PhysicalMemory No such file or directory

Any suggestions?

Interestingly enough, I can pop in a Helix CD and have it do a memory snapshot without any problem.


   
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keydet89
(@keydet89)
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I've been having a few problems doing memory dumps with dd and dcfldd on an XP Pro workstation, and I was wondering if anyone might be able to give me a bit of insight as to what I might be doing wrong.

When I open a command prompt and type in any variation on the following (with both dd and dcfldd - as well as with conv=sync,noerror and other options)

dcfldd if=\\.\PhysicalMemory of=dump.dd

I get the following error message

dcfldd\\.\PhysicalMemory No such file or directory

Any suggestions?

Interestingly enough, I can pop in a Helix CD and have it do a memory snapshot without any problem.

No suggestions, but a questions…why are you using dcfldd to dump the contents of PhysicalMemory?


   
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azrael
(@azrael)
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Joined: 19 years ago
Posts: 656
 

Suggestion -)

Try using


dcfldd if=\\\\.\\PhysicalMemory of=dump.dd

Apologies for not having been able to test this, but it seems similar to http//www.forensicfocus.com/index.php?name=Forums&file=viewtopic&t=2037


   
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azrael
(@azrael)
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Joined: 19 years ago
Posts: 656
 

Suggestion -)

Try using


dcfldd if=\\\\.\\PhysicalMemory of=dump.dd

Apologies for not having been able to test this, but it seems similar to http//www.forensicfocus.com/index.php?name=Forums&file=viewtopic&t=2037

Heh - I tested it, and it doesn't work -P Well, was only a suggestion 😉


   
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keydet89
(@keydet89)
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Perhaps as a way to answer my own question, I found this

http//www.forensicmag.com/articles.asp?pid=179

This page states that "The latest version of DCFLDD is available for download at http//dcfldd.sourceforge.net/.", and that the \\.\PhysicalMemory syntax works. The authors state that this works.

I downloaded the latest available version (1.34), and ran it on my XP SP2 system…results follow

D\tools\dcfldd>dcfldd if=\\.\PhysicalMemory
dcfldd\\.\PhysicalMemory No such file or directory

This syntax is also stated here
http//www.techsec.com/pdf/Wednesday/Network%20Investigations%20-%20Farwell.pdf

Oh, well…


   
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azrael
(@azrael)
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Joined: 19 years ago
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Hmmm …
All good fun really …
I've been fiddling and …

I can get results out of

dcfldd.exe if=/dev/mem of=memdump.dd conv=sync,noerror
It generates a few odd messages in the process …


snip ...

dcfldd/dev/mem Invalid argument
26+7 records in
33+0 records out
dcfldd/dev/mem Invalid argument
26+8 records in
34+0 records out
dcfldd/dev/mem Invalid argument
26+9 records in
35+0 records out
16128 blocks (504Mb) written.
16357+11 records in
16368+0 records out

But, at the end of it all, generates a 511.5 meg file for my supposed 512 meg of memory from this test machine …

21/12/2007 1057 536,346,624 dump.dd
Looking at the file ( not actually _processing_ it - just visual ), it looks like it may well be the memory dump …


   
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erowe
(@erowe)
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Joined: 18 years ago
Posts: 144
Topic starter  

Thanks for all the input - the /dev/mem worked for me too although just as with Azrael's dump the output file seems a little small.

/dev/mem had (briefly) crossed my mind, but I figured it would only work on Unix/Linux/MAC boxes.

As for why I was doing all this; I'm working on putting together some tools for a live response CD.

Any suggestions on alternative tools to dump memory with, or tools to carve/analyze the dumps?

I know FTK can carve out cached images as well as index the dumps for text searches, but I was wondering if anyone else had any favourite tools to recommend.


   
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keydet89
(@keydet89)
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Hmmm …
All good fun really …
I've been fiddling and …

[snip]

But, at the end of it all, generates a 511.5 meg file for my supposed 512 meg of memory from this test machine …

What was the test machine? Linux? XP? If XP…one has to wonder what is being accessed as "/dev/mem".

Azrael, can you provide any insight?

H


   
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keydet89
(@keydet89)
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…I was wondering if anyone else had any favourite tools to recommend.

Windows Forensic Analysis


   
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azrael
(@azrael)
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Joined: 19 years ago
Posts: 656
 

Hmmm …
All good fun really …
I've been fiddling and …

[snip]

But, at the end of it all, generates a 511.5 meg file for my supposed 512 meg of memory from this test machine …

What was the test machine? Linux? XP? If XP…one has to wonder what is being accessed as "/dev/mem".

Azrael, can you provide any insight?

H

Sure. Sorry - WinXP SP 2 -) I have to agree that it isn't clear exactly what it _is_ accessing … The size is interesting, but close enough to suggest that something to do with memory has happened, and the contents, of my dump at least "look" promising …


   
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