Understanding files

  • masterkey_blob: A DPAPI master key file (encrypted with the user’s password/SID).
  • credential_blob: A DPAPI-encrypted credential file (e.g., saved passwords from tools like Credential Manager).

Decrypting the Master Key

The first command to decrypt the masterkey_blob and obtain the decrypted master key:

impacket-dpapi masterkey -file masterkey_blob -password 'password' -sid S-1-5-21-14****
Impacket v0.13.0.dev0 - Copyright Fortra, LLC and its affiliated companies
 
...
 
Decrypted key with User Key (MD4 protected)
Decrypted key: 0xd9a570722fbaf***
  • -password: The user’s password, used to derive the decryption key.
  • -sid: The Security Identifier (SID) of the user account. DPAPI keys are tied to a user’s SID.

This is the decrypted master key (hex format), derived using the user’s password and SID.

Decrypting the Credential Blob

Now to decrypt the credential_blob, we need to make some adjustments and use the master key we obtain earlier:

impacket-dpapi credential -f credential_blob -key 0xd9a570722fbaf***
Impacket v0.13.0.dev0 - Copyright Fortra, LLC and its affiliated companies
 
[CREDENTIAL]
...
Description :
Unknown     :
Username    : username
Unknown     : password