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EnCase Forensic Version 6.11 Userʹs Guide
Performing Acquisitions with LinEn
The EnCase LinEn utility provides the following methods of acquiring evidence from a subject
drive:
Drive‐to‐drive acquisitions
Crossover cable acquisitions
Drive‐to‐drive acquisitions provide the means to safely preview and acquire devices without
using a hardware write blocker. Drive‐to‐drive acquisitions use either the subject machine or the
forensic machine to perform the acquisitions. The Drive‐to‐drive acquisition speed can be
significantly faster than EN.EXE and MS‐ DOS from previous versions, simply because Linux is
a 32‐bit operating system.
Crossover cable acquisitions require both a subject and forensic machine. This type of acquisition
also negates the need for a hardware write blocker; however, it lends itself to situations where
access to the subject machineʹs drive are difficult or not practical. This is the recommended
method for acquiring laptops and exotic RAID arrays. This method is slower than a Drive‐to‐
drive acquisition because data is transferred over a network cable, and thus is especially
sensitive to the speed of the network cards housed in both machines.
Setup for a Drive-to-Drive Acquisition
When a subject drive from the subject machine cannot be acquired via a crossover cable
acquisition, the subject drive can be acquired via a drive‐to‐drive acquisition. Drive‐to‐drive
acquisitions can be done in the following ways:
Running a LinEn boot disc on the forensic machine
Running the LinEn utility from Linux already installed on the forensic machine
Running a LinEn boot disc on the subject machine
Any of these cables can be used as a hard disk cable:
IDE Cable
USB Cable
Firewire
SATA
SCSI
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Figure 3
Setups for Drive‐to‐drive acquisitions with 1) the forensic machine, running LinEn from the
LinEn Boot Disk, connected to the subject hard drive; 2) the forensic machine, booted to Linux and
running LinEn, connected to the subject hard drive; 3) subject machine, running LinEn from the LinEn
Boot Disk , connected to the target hard drive.
Doing a Drive-to-Drive Acquisition Using LinEn
Once LinEn is set up, run LinEn, choose Acquire, then select the drive to be acquired and the
storage path. Optionally, provide additional metadata.
Configure LinEn as described in LinEn Setup, and verify that autofs is disabled (unchecked).
The investigator has identified the subject drive to be acquired and the storage drive that will
hold the acquired evidence file.
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EnCase Forensic Version 6.11 Userʹs Guide
1.
If the FAT32 storage partition to be acquired has not been mounted, mount the FAT32
storage partition.
2.
Navigate to the folder where LinEn resides and type ./linen in the console to run LinEn.
The LinEn Main Screen displays.
3.
Select Acquire.
The Acquire screen displays.
4.
Choose the physical drive or logical partition you wish to acquire.
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The Acquire Device dialog displays.
5.
For the data elements requested by the Acquire dialog, either accept the default, or enter
a value or choose one of the alternatives, as described in Specifying and Running an
Acquisition.
6.
Press Enter.
The Acquire Device dialog requests additional data values until all data elements have
been entered or selected. Then, the Creating File dialog displays.
7.
When the acquisition is complete, click OK.
The LinEn main window displays. The subject has been acquired and is stored on the
storage drive.
8.
Connect the storage drive to investigatorʹs machine.
9.
Add the EnCase evidence file using the Sessions Sources page of the Add Device Wizard,
as described in Completing the Sessions Sources Page
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EnCase Forensic Version 6.11 Userʹs Guide
Acquiring Device Configuration Overlays (DCO) and Host Protected Areas (HPA)
EnCase applications can detect and image DCO and/or HPA areas on any ATA‐6 or higher‐level
disk drive. These areas are detected using LinEn (Linux) or the FastBloc SE module. EnCase
applications running in Windows with a hardware write blocker will not detect DCOs or HPAs.
The application now shows if a DCO area exists in addition to the HPA area on a target drive.
FastBloc SE is a separately purchased component.
HPA is a special area located at the end of a disk. It is usually configured so the casual observer
cannot see it, and can only be accessed by reconfiguring the disk. HPA and DCO are extremely
similar; the difference is the SET_MAX_ADDRESS bit setting that allows recovery of a removed
HPA at reboot. When supported, EnCase applications see both areas if they coexist on a hard
drive. For more information, see the EnCase Modules Manual.
Acquiring a Disk Running in Direct ATA Mode
If the Linux distribution supports ATA mode, you will see a Mode option. The mode must be set
before the disk is acquired. An ATA disk can be acquired via the drive‐to‐drive method. The
ATA mode is useful for cases when the evidence drive has a host protected area (HPA) or drive
control overlay (DCO). Only Direct ATA Mode can review and acquire these areas.
LinEn is configured as described in LinEn Setup, and autofs is disabled (unchecked). Linux is
running in Direct ATA Mode.
To acquire a disk running in Direct ATA Mode:
1.
If the FAT32 storage partition to be acquired has not been mounted, mount the FAT32
storage partition.
2.
Navigate to the folder where LinEn resides and type ./linen in the console.
The LinEn Main Screen displays.
3.
Select Mode, then select Direct ATA Mode.
The disk running in ATA mode can now be acquired.
4.
Continue the drive‐to‐drive acquisition with Step 3 of Doing a Drive‐toDrive Acquisition
Using LinEn.
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