Difference between pages "Internet Explorer" and "Encase image file format"

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[[EnCase]] uses a closed format for images which is reportedly based on [http://www.asrdata.com/SMART/whitepaper.html ASR Data's Expert Witness Compression Format]. The evidence files, or E01 files, contain a physical bitstream of an acquired disk, prefixed with a '"Case Info" header, interlaced with CRCs for every block of 64 x 512 byte sectors (32 KiB), and followed by a footer containing an MD5 hash for the entire bitstream.  Contained in the header are the date and time of acquisition, an examiner's name, notes on the acquisition, and an optional password; the header concludes with its own CRC.
  
Internet Explorer is the default [[Web Browser]] included with [[Microsoft Windows]].
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EnCase can store media data into multiple evidence files, which are called segment files. Each segment file consist of multiple sections. Each section consist of a section start definition. This contains a section type.
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Up to EnCase 5 the segment file were limited to 2 GiB, due to the internal 31-bit file offset representation. This limitation was lifted using a base offset work around in EnCase 6.
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At least from Encase 3 the case info header is contained in the "header" section, which is defined twice within the file and contain the same information.
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With Encase 4 an additional "header2" section was added. The "header" section now appears only once, but the new "header2" section twice.
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Version 3 of The Encase F introduced an "error2" sections that it uses to record the location and number of bad sector chunks. The way it handles the sections it can't read is that those areas are filled with zero. Then Encase displays to the user the areas that could not be read when the image was acquired. The granularity of unreadable chunks appears to be 32K.
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Within Encase 5 the amount of sectors per block (chunk) can vary.
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Encase from at least in version 3, 4 and 5 can hash the data of the media it acquires.
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It does this by calculating a MD5 hash of the original media data and adds a hash section
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to the last of the segment files.
  
 
== See Also ==
 
== See Also ==
  
* [[Internet Explorer History File Format]]
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[[EnCase]]
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== External Links ==
  
== External Links ==
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* A great deal of information about the format has been documented by the [http://libewf.sourceforge.net libewf project], including some of the [http://downloads.sourceforge.net/libewf/ewf_file_format.pdf E01 file format specifications].
* [http://kb.digital-detective.co.uk/display/NetAnalysis1/Internet+Explorer+Cache Internet Explorer Cache]
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* [http://www.cfreds.nist.gov/v2/Basic_Mac_Image.html Sample image in EnCase, iLook, and dd format] - From the [[Computer Forensic Reference Data Sets]] Project
* [http://support.microsoft.com/kb/182569 Internet Explorer security zones registry entries for advanced users], by [[Microsoft]]
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* [http://www.swiftforensics.com/2011/09/internet-explorer-recoverystore-aka.html Internet Explorer RecoveryStore (aka Travelog) as evidence of Internet Browsing activity], by [[Yogesh Khatri]], September 29, 2011
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[[Category:Applications]]
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[[Category:Forensics File Format]]
[[Category:Web Browsers]]
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Revision as of 05:19, 31 January 2009

EnCase uses a closed format for images which is reportedly based on ASR Data's Expert Witness Compression Format. The evidence files, or E01 files, contain a physical bitstream of an acquired disk, prefixed with a '"Case Info" header, interlaced with CRCs for every block of 64 x 512 byte sectors (32 KiB), and followed by a footer containing an MD5 hash for the entire bitstream. Contained in the header are the date and time of acquisition, an examiner's name, notes on the acquisition, and an optional password; the header concludes with its own CRC.

EnCase can store media data into multiple evidence files, which are called segment files. Each segment file consist of multiple sections. Each section consist of a section start definition. This contains a section type.

Up to EnCase 5 the segment file were limited to 2 GiB, due to the internal 31-bit file offset representation. This limitation was lifted using a base offset work around in EnCase 6.

At least from Encase 3 the case info header is contained in the "header" section, which is defined twice within the file and contain the same information.

With Encase 4 an additional "header2" section was added. The "header" section now appears only once, but the new "header2" section twice.

Version 3 of The Encase F introduced an "error2" sections that it uses to record the location and number of bad sector chunks. The way it handles the sections it can't read is that those areas are filled with zero. Then Encase displays to the user the areas that could not be read when the image was acquired. The granularity of unreadable chunks appears to be 32K.

Within Encase 5 the amount of sectors per block (chunk) can vary.

Encase from at least in version 3, 4 and 5 can hash the data of the media it acquires. It does this by calculating a MD5 hash of the original media data and adds a hash section to the last of the segment files.

See Also

EnCase

External Links