Difference between pages "Determining OS version from an evidence image" and "SuperFetch"

From ForensicsWiki
(Difference between pages)
Jump to: navigation, search
(Windows 2000/2003/XP/Vista)
 
 
Line 1: Line 1:
One of the first steps an examiners will need to carry out once they have an evidence image is to log system metadata, including OS version and patch level. This may be of particular importance if the image in question is from a machine that is suspected of having been compromised.
+
{{Expand}}
  
==Windows==
+
SuperFetch is a performance enhancement introduced in [[Microsoft]] [[Windows|Windows Vista]] to reduce the time necessary to launch applications. SuperFetch works with the memory manager service in Windows to analyze memory usage patterns over time to determine the optimal memory content for a given user for a date or time of day. This differs from the [[Prefetch]] technique used in Microsoft Windows XP, which preloads data into memory without analyzing usage patterns.
  
===Windows 95/98/ME===
+
From [http://msdn.microsoft.com/en-us/library/windows/hardware/dn653317(v=vs.85).aspx]: SuperFetch prioritizes the following kinds of pages to remain in memory:
 +
* Pages of applications that are used most frequently overall.
 +
* Pages of applications that are commonly used when resuming:
 +
** After extensive hibernation (for example, first thing in the morning).
 +
** After shorter periods of sleep or hibernation (for example, after lunch).
  
Establish the boot volume, verify that it is a FAT file system, and locate the hidden text file \MSDOS.SYS. Locate the [Options]WinVer parameter:
+
If SuperFetch detects that the system drive is a fast solid-state drive (SSD) (as measured by Windows Experience Index Disk score), then SuperFetch turns off [[ReadyBoot]].
  
{| class="wikitable"
 
|-
 
! WinVer
 
! OS
 
|-
 
| 4.00.0950
 
| Windows 95
 
|-
 
| 4.00.1111
 
| Windows 95 OSR2
 
|-
 
| 4.03.1212
 
| Windows 95 OSR2.1
 
|-
 
| 4.03.1214
 
| Windows 95 OSR2.5
 
|-
 
| 4.10.1998
 
| Windows 98
 
|-
 
| 4.10.2222
 
| Windows 98 SE
 
|-
 
| 4.90.3000
 
| Windows ME
 
|}
 
  
Alternatively, establish WinDir ([Paths]WinDir in \MSDOS.SYS), locate the %WINDIR%\SYSTEM.DAT registry file. Next, look up the registry key Software\Microsoft\Windows\CurrentVersion\, and values Version and VersionNumber. (Backup copies of SYSTEM.DAT may be found in .CAB files in %WINDIR%\SYSBCKUP.)
+
== Configuration ==
  
===Windows NT4===
+
Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the <tt>HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnableSuperfetch</tt> [[Registry]] key [http://www.codinghorror.com/blog/archives/000688.html]. A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, <tt>services.msc</tt> [http://tiredblogger.wordpress.com/2007/03/27/superfetch-not-so-super-for-gaming/].
  
===Windows 2000, XP, 2003, Vista ===
+
== File Formats ==
Information about a running system can be displayed using the command `ver` (and `systeminfo` on some systems).
+
  
During a forensic examination, information regarding the version of Windows can be found in a number of places.  For example, by default, the Windows directory on Windows XP is "C:\Windows", where on Windows NT and 2000, it was "C:\Winnt". This is not definitive, however, because this directory name is easily modified during installation.
+
Data for SuperFetch is gathered by the <tt>%SystemRoot%\System32\Sysmain.dll</tt>, part of the Service Host process, <tt>%SystemRoot%\System32\Svchost.exe</tt>, and stored in a series of files in the <tt>%SystemRoot%\Prefetch</tt> directory [http://www.microsoft.com/technet/technetmag/issues/2007/03/VistaKernel/]. These files appear to start with the prefix <tt>Ag</tt> and have a <tt>.db</tt> extension. The format of these files is not fully known, there is available unofficial partial specification [http://blog.rewolf.pl/blog/?p=214] and open source (GPL) dumper for .db files [http://code.google.com/p/rewolf-superfetch-dumper/]. Some information can be gleaned from these files by searching for [[Unicode]] [[strings]] in them.
  
Determining the version of Windows from the Software Registry Hive file - navigate to the ''Microsoft\Windows NT\CurrentVersion'' key, and examine the values beneath the key; specifically, values such as ProductName, CSDVersion, ProductId (if available), BuildLab, and on Vista, BuildLabEx.
+
The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [http://channel9.msdn.com/showpost.aspx?postid=242429].
  
Determining the version of Windows from file version information - locate the file %WinDir%\system32\ntoskrnl.exe and review the file version information/strings from the resource section of the PE file.  You can view this information with a hex editor, or extract it using a variety of means.  There is a Perl module (Win32::File::VersionInfo) that will allow you to extract this information, and the Perl script [http://sourceforge.net/project/showfiles.php?group_id=164158&package_id=203967 kern.pl] illustrates a platform independent means of examining the PE header and ultimately locating the file version information.
+
== See Also ==
 +
* [[Prefetch]]
 +
* [[ReadyBoost]]
 +
* [[ReadyBoot]]
 +
* [[Windows SuperFetch Format|SuperFetch Format]]
 +
* [[Windows]]
  
In order to determine the difference between Windows XP Professional and Home versions, look for the %WinDir%\system32\prodspec.ini file; it contains information regarding the Product type (either XP Pro or Home). Another way to do this is to look at Microsoft Product Code (first 5 digits of ''Product ID''). Some of these values:
+
== External Links ==
 +
* [http://en.wikipedia.org/wiki/Windows_Vista_I/O_technologies#SuperFetch Wikipedia: Windows Vista I/O technologies - SuperFetch]
 +
* [http://channel9.msdn.com/showpost.aspx?postid=242429 Channel 9 Interview with Michael Fortin of Microsoft on SuperFetch]
 +
* [http://www.informationweek.com/news/showArticle.jhtml?articleID=196902178 Microsoft Predicts The Future With Vista's SuperFetch] from Information Week
 +
* [http://jessekornblum.com/presentations/dodcc08-2.pdf DC3 Presentation: My You Look SuperFetching], by Jesse Kornblum
  
{| class="wikitable" border="1"
+
== Tools ==
|-
+
=== Open Source ===
!Value (MPC)!!Version
+
* [https://code.google.com/p/rewolf-superfetch-dumper/ rewolf-superfetch-dumper]
|-
+
|55034 || Windows XP Professional English
+
|-
+
|55683 || Windows XP Professional Russian
+
|-
+
|55681 || Windows XP Home Edition Russian
+
|}
+
  
=== Other ===
+
[[Category:Windows]]
* Windows 2008
+
* Windows 7
+
* Windows 8
+
 
+
Different editions per version?
+
 
+
==Unix/Linux==
+
Information about a running system, including the kernel version, can be displayed using the command `uname -a`. However, this is not much good if you performing dead analysis on a disk image.
+
 
+
===Linux===
+
A number of Linux distributions create a file in ''/etc'' to identify the release or version installed.
+
 
+
<pre>
+
/etc/issue
+
/etc/issue.net
+
</pre>
+
 
+
{| class="wikitable" border="1"
+
|-
+
!Distro!!Tag
+
|-
+
|Red Hat || /etc/redhat-release
+
|-
+
|Debian  || /etc/debian-version
+
|}
+
 
+
=== (Open) Solaris ===
+
 
+
===Free/Net/OpenBSD===
+
A first indicator of the presence of a BSDs operating system is the partition table on a MBR-partitioned disk:
+
 
+
{| class="wikitable" border="1"
+
|-
+
!OS!!Partition type
+
|-
+
|FreeBSD || FreeBSD (0xA5)
+
|-
+
|OpenBSD || OpenBSD (0xA6)
+
|-
+
|NetBSD || NetBSD (0xA9)
+
|-
+
|}
+
 
+
You can get the release and version of BSDs operating system inside the kernel images, even with only a disk image.
+
 
+
{| class="wikitable" border="1"
+
|-
+
!OS!!Kernel path
+
|-
+
|FreeBSD || /boot/kernel/kernel
+
|-
+
|OpenBSD || /bsd
+
|-
+
|NetBSD || /netbsd
+
|-
+
|}
+
 
+
You can use <tt>strings</tt> and <tt>grep</tt> tools to find this information with <tt>strings kernel_path | grep os_name</tt>. (e.g.: <tt>strings /bsd | grep OpenBSD</tt>)
+
 
+
===AIX===
+
 
+
===HP/UX===
+
 
+
===Other===
+
* BSDI
+
 
+
==Other==
+
* Plan9
+
* QNX RTOS
+
* OS2
+
* MacOS-X/IOS
+
* DOS
+
 
+
[[Category:Howtos]]
+

Revision as of 02:48, 24 April 2014

Information icon.png

Please help to improve this article by expanding it.
Further information might be found on the discussion page.

SuperFetch is a performance enhancement introduced in Microsoft Windows Vista to reduce the time necessary to launch applications. SuperFetch works with the memory manager service in Windows to analyze memory usage patterns over time to determine the optimal memory content for a given user for a date or time of day. This differs from the Prefetch technique used in Microsoft Windows XP, which preloads data into memory without analyzing usage patterns.

From [1]: SuperFetch prioritizes the following kinds of pages to remain in memory:

  • Pages of applications that are used most frequently overall.
  • Pages of applications that are commonly used when resuming:
    • After extensive hibernation (for example, first thing in the morning).
    • After shorter periods of sleep or hibernation (for example, after lunch).

If SuperFetch detects that the system drive is a fast solid-state drive (SSD) (as measured by Windows Experience Index Disk score), then SuperFetch turns off ReadyBoot.


Configuration

Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnableSuperfetch Registry key [2]. A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, services.msc [3].

File Formats

Data for SuperFetch is gathered by the %SystemRoot%\System32\Sysmain.dll, part of the Service Host process, %SystemRoot%\System32\Svchost.exe, and stored in a series of files in the %SystemRoot%\Prefetch directory [4]. These files appear to start with the prefix Ag and have a .db extension. The format of these files is not fully known, there is available unofficial partial specification [5] and open source (GPL) dumper for .db files [6]. Some information can be gleaned from these files by searching for Unicode strings in them.

The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [7].

See Also

External Links

Tools

Open Source