What is a DCSync attack?
A DCSync attack occurs when attackers impersonate a domain controller (DC) to retrieve sensitive information, such as password hashes for domain accounts, directly from AD. This type of attack is dangerous because it gives attackers near-complete access to an organization’s network.
How does the attack work?
In a DCSync attack, the threat actor takes advantage of the Directory Replication Service (DRS) Remote Protocol to trick a DC into sharing sensitive data like password hashes. Here is how it works in three steps:
- Gaining privileges: First, the attacker finds a way to gain high-level permissions in AD, usually by obtaining Domain Admin or Enterprise Admin rights, which are necessary for accessing replication features.
- Requesting replication: Next, the attacker uses tools like Mimikatz to request a replication of AD data. By pretending to be a legitimate DC, they exploit AD’s own replication process.
- Extracting data: Acting as a DC, the attacker can now pull sensitive data, like password hashes, which they can crack offline or use to log in across the domain. This gives them unauthorized access to resources throughout the network.
How do you protect against DCSync attacks?
Defending against DCSync attacks requires stronger security practices, vigilant monitoring of AD, and implementing strict restrictions. Here are four important steps to help protect against these attacks:
Limit privileged access
- Restrict high-level access groups like Domain Admins and Enterprise Admins to essential personnel only.
- Use privileged access management to enforce just in time access, so accounts only have elevated privileges when absolutely needed.
- Set up a tiered access model that organizes administrative accounts by role and security level.
- Apply strong network segmentation to control where privileged accounts are allowed to log in.
Enable and monitor logging
- Enable advanced audit policies to monitor events like 4662 (for sensitive object access) and 4624 (account logon events).
- Use comprehensive AD auditing solutions to detect unusual replication requests, such as a workstation requesting DCSync operations.
Implement credential protection
- Use Managed Service Accounts and Group Managed Service Accounts to protect service accounts.
- Employ Local Administrator Password Solution to manage local administrator passwords.
- Enable AES encryption for Kerberos to strengthen the security of ticket exchanges.
- Regularly rotate KRBTGT account passwords to limit the use of Golden Tickets if an account is compromised.
Train and test
- Conduct regular security awareness training to educate privileged users on AD security practices.
- Perform attack simulation exercises to test the effectiveness of defenses against DCSync and other AD-related attacks.
How does ADAudit Plus help with DCSync attack detection?
ManageEngine ADAudit Plus' Attack Surface Analyzer features curated dashboards and specialized reports that help you detect and respond to DCSync attacks in real time. Powered by exclusive rules derived from the MITRE ATT&CK® framework, the Attack Surface Analyzer delivers invaluable threat insights, enabling you to investigate potential DCSync attacks in just a few clicks.
-
Gain invaluable threat insights about your AD environment from Attack Surface Analyzer's exclusive dashboard.
-
Drill down into granular details about when an attack was perpetrated, by whom, from which machine, and its impact.
-
Get a detailed history of the threat actor's actions immediately before and after an attack is detected.
Start protecting your on-premises and cloud AD resources with ADAudit Plus
Detect over 25 different AD attacks and identify potential misconfigurations within your Azure, GCP, and AWS cloud environments with the Attack Surface Analyzer.
See the Attack Surface Analyzer in actionWe're thrilled to be recognized as a Gartner Peer Insights Customers' Choice for Security Incident & Event Management (SIEM) for the fourth year in a row.
Don't risk your AD security
With ADAudit Plus you can:
- Detect 25+ AD attacks
- Receive instant security alerts
- Initiate rapid threat response
