👉 Overview
👀 What ?
Windows DCShadow is a technique used by attackers to manipulate an organization's Active Directory (AD) data. It's part of the Mimikatz toolkit, a popular password stealing utility. DCShadow involves the attacker registering a rogue domain controller (DC) that can then send illegitimate updates to other DCs within the network, allowing manipulation of AD objects.
🧐 Why ?
Understanding DCShadow is crucial as it represents a significant security threat. It allows an attacker to make unsanctioned changes to the AD, such as escalating privileges or creating new security principals. These modifications can then be used for further attacks or to maintain persistence within the environment. Furthermore, DCShadow attacks can be difficult to detect, making them a potent tool in the hands of a skilled adversary.
⛏️ How ?
Implementing DCShadow involves several steps: first, compromising an existing account with high-level permissions in the AD, such as a domain admin. Then, using Mimikatz to register a rogue DC and create a replication request for the AD object you intend to modify. It's important to note that using DCShadow is illegal and unethical unless you're authorized to perform penetration testing. On the defense side, monitoring for unusual replication requests and restricting high-level permissions can help protect against DCShadow attacks.
⏳ When ?
DCShadow was first introduced as part of the Mimikatz toolkit in early 2018. Since then, it's been used in numerous cybersecurity attacks and penetration testing exercises.
⚙️ Technical Explanations
At the technical level, DCShadow involves registering a rogue domain controller (DC) within the Active Directory (AD). This is done by compromising a high-privileged account and using it to create a new server object in the AD's configuration partition. This new server is then linked to the compromised account and configured as a DC, essentially giving the attacker control over a DC within the network. The attacker can then use this rogue DC to send replication requests to other DCs in the network, allowing them to manipulate AD objects as they see fit.