Difference between revisions of "Windows Prefetch File Format"

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(Header format 17)
(Header format)
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{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
 +
! Field
 
! Offset
 
! Offset
 
! Length
 
! Length
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! Notes
 
! Notes
 
|-
 
|-
 +
| H1
 
| 0x0000
 
| 0x0000
 
| 4
 
| 4
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0x00000017 - Vista, Windows 7
 
0x00000017 - Vista, Windows 7
 
|-
 
|-
 +
| H2
 
| 0x0004
 
| 0x0004
 
| 4
 
| 4
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| ? Probably a file type magic number. Observed value: 0x41535353
 
| ? Probably a file type magic number. Observed value: 0x41535353
 
|-
 
|-
 +
| H3
 
| 0x0008
 
| 0x0008
 
| 4
 
| 4
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| ? Observed values: 0x00 00 00 0F - Windows XP
 
| ? Observed values: 0x00 00 00 0F - Windows XP
 
|-
 
|-
 +
| H4
 
| 0x000C
 
| 0x000C
 
| 4
 
| 4
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| Prefetch file length.
 
| Prefetch file length.
 
|-
 
|-
 +
| H5
 
|0x0010
 
|0x0010
 
| 60
 
| 60
 
| USTR
 
| USTR
| Name of executable as Unicode string, truncated after character 29 if necessary, and terminated by U+0000.  
+
| Name of executable as Unicode string, truncated after character 29 if necessary, and terminated by U+0000. As it appears in the preftech file file name.
 
|-
 
|-
 +
| H6
 
|0x004C
 
|0x004C
 
|4
 
|4
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|}
 
|}
  
It's worth noting that the name of a carved prefetch file can be restored using the information in bytes 0x0010--0x004F
+
It's worth noting that the name of a carved prefetch file can be restored using the information in field H5 and H6
  
 
=== Format 23 ===
 
=== Format 23 ===

Revision as of 11:00, 14 September 2011

A Windows Prefetch file consists of one file header and multiple file sections with different content. Not all content has an obvious forensic value.

As far as have been possible to ascertain, there is no public description of the format. The description below has been synthesised from examination of multiple prefetch files.

Header

Header format

This format has been observed on Windows XP, ... may need to be duplicated for Vista/Win7 format

Field Offset Length Type Notes
H1 0x0000 4 DWORD  ? Probably a version number, identifying the file structure. Observed values:

0x00000011 - Windows XP 0x00000017 - Vista, Windows 7

H2 0x0004 4 DWORD  ? Probably a file type magic number. Observed value: 0x41535353
H3 0x0008 4  ?  ? Observed values: 0x00 00 00 0F - Windows XP
H4 0x000C 4 DWORD Prefetch file length.
H5 0x0010 60 USTR Name of executable as Unicode string, truncated after character 29 if necessary, and terminated by U+0000. As it appears in the preftech file file name.
H6 0x004C 4 DWORD The prefetch hash, as it appears in the pf file name.
...

It's worth noting that the name of a carved prefetch file can be restored using the information in field H5 and H6

Format 23

Section A and B

These two sections have no obvious forensic value.

Section C

Section D