kdablock.blogg.se - Backup service master key

Tools t hat can aid in automating the process of the above steps include Mimikatz, SharpDPAPI, DSInternals, Impacket, and DonAPI.

In some misconfigured environments, we observed broader access to users’ files, which allowed any user in the domain to read various encrypted blobs.

The secret blob location depends on the configuration of the storing application, but it will generally be found somewhere under the user’s profile path, which may require part of, or the same access, as above.

Usually stored under a user’s profile path (% USERPROFILE%).

Requires access to read secret data, AKA secret blob.

Decrypt secret blobs that are tied to the decrypted Master Key.

Requires access to users’ roaming profiles access to a profile can be achieved by using a user’s credentials, or by obtaining local administrator access to a machine where the user is logged on, or using admin access to the file share in which roaming profiles are stored.

Requires a set of specific permissions that are commonly found in Domain Admin accounts.

Dump the domain backup key from a Domain Controller.

The following steps are commonly taken by threat actors to create a successful attack path that exploits the DPAPI backup key to extract sensitive data, such as browser credentials:

Get new tools that automate the process.Replacing the backup key as part of a remediation process.This article will familiarize you with the following:

Today, we are going to change this reality! Setting expectations Currently, the only way to properly replace the key is by re-building the domain. The domain backup key is a unique RSA key pair that is generated only once during the domain inception. The encrypted copy is made for recovery purposes, and allows users to recover encrypted secrets if they forgot their password. įor Active Directory users, the Master Key is encrypted with the user's password, and another copy of the key is encrypted with the domain backup key. Replacing this key enables defenders to eliminate the ability of threat actors to indefinitely exploit a compromised key, and decrypt users’ secrets.ĭata Protection API (DPAPI) is a widely-used functionality within Windows applications that encrypts sensitive data, without implementing the underlying encryption algorithm itself.Įvery Windows user has a DPAPI Master Key that can be used to encrypt and decrypt data this data may be stored either locally or remotely. In this post, we demonstrate for the first time how defenders can replace their DPAPI backup key, to better defend their organization during or following an Active Directory compromise event. In recent years, the Windows DPAPI mechanism has been exploited by threat actors to extract secrets across an organization, using the immutable DPAPI domain backup key as a kind of ‘joker’ during the attack.