Passware Kit scans the physical memory image file (acquired while the encrypted disk was mounted, even if the target computer was locked), extracts all the encryption keys, and decrypts the given volume. Such memory images can be acquired using Passware FireWire Memory Imager (included in Passware Kit Forensic, has limitations), or third-party tools, such as ManTech Physical Memory Dump Utility, Perlustro IXImager or win32dd.
If the target computer with the encrypted volume is powered off, encryption keys are not stored in its memory, but they could be possibly recovered from the hiberfil.sys file, which is automatically created when a system hibernates.
NOTE: If the target computer is turned off and the encrypted volume was dismounted during the last hibernation, neither the memory image nor the hiberfil.sys file will contain the encryption keys. Therefore, instant decryption of the volume is impossible. In this case, Passware Kit assigns brute-force attacks to recover the original password for the volume.
Overall Disk Decryption Steps
- Acquire a memory image of or take the hiberfil.sys file from the target computer.
- Create an encrypted disk image (not required for TrueCrypt).
- Run Passware Kit to recover the encryption keys and decrypt the hard disk.
Below are the steps to decrypt a hard disk image. Please, refer to Passware Kit Help for the detailed instructions.
Acquiring Memory Image Using Passware FireWire Memory Imager
If the target computer is turned off, but the encrypted volume was mounted during the last hibernation, skip this step. Take the hibefil.sys file from the target computer or its hard drive image and use this file as a memory image for decryption.
Requirements for Memory Acquisition:
- The target computer is turned on and the encrypted volume is mounted.
- Both the target computer and the computer used for acquisition have FireWire (IEEE 1394) ports.
- A FireWire cable.
1. On the Passware Kit Start Page click Memory Analysis, and then click Passware FireWire Memory Imager:
The following screen appears:
Insert a blank USB flash drive and click Next.
2. Passware Kit copies the necessary files on the USB flash drive. The Passware FireWire Memory Imager USB drive is ready:
3. Restart your computer.
4. Passware FireWire Memory Imager starts:
5. Connect the target computer with a FireWire cable. Press Next.
6. The memory imaging process starts:
7. Unplug the FireWire cable, remove the USB flash drive, and press Reboot to restart your PC.
8. The memory image of the target computer (a memory.bin file) is created on the USB flash drive.
Decrypting the Hard Disk
Passware Kit can work with either a TrueCrypt volume file (.TC, encrypted file container), or with its image. For BitLocker/FileVault2/PGP decryption, Passware Kit works with image files of encrypted disks. Disk volume images can be created using third-party tools, such as Guidance EnCase, Free EASIS Drive Cloning, or DD.
1. Click Full Disk Encryption on the Passware Kit Start Page. This displays the screen shown below:
2. Click on the corresponding encryption type, e.g. TrueCrypt. This displays the screen shown below:
3. Click Browse… and locate the encrypted volume file or its image file.
4. Click Browse… and locate the physical memory image (memory.bin) or the hiberfil.sys file from the computer to which your encrypted volume was mounted.
NOTE: If the target computer is turned off and the encrypted volume was dismounted during the last hibernation, neither the memory image nor the hiberfil.sys file will contain the encryption keys. Therefore, instant decryption of the volume is impossible. In this case, switch to “The volume is dismounted” option, and Passware Kit will assign brute-force attacks to recover the password for the volume.
5. For TrueCrypt, FileVault2 and PGP decryption, click Browse… and select the location and name of the destination file (the image of the decrypted volume).
6. Click Next.
This procedure initiates the decryption process. The decryption might take several minutes depending on the size of the memory image file. The figure below shows a sample result.
Now you can open your hard disk using the encryption key recovered, or extract an image of the decrypted disk.