Last Updated on May 26, 2021 by Philip Robinson
Active Directory security groups are used to give users or groups access to certain resources. If your Active Directory security groups are mis-configured or compromised, then your sensitive data could be at risk.
In this article, I’m going to go through some best practices for your Active Directory security groups to ensure that you can maintain the security of your AD.
Ensure Default Security Groups Do Not Have Elevated Permissions
Whenever an Active Directory domain is set up, a default security group is set up. Sometimes, these default security groups will have excessive permissions that may lead to users being granted access to resources and data that they do not need.
Ensure that your users only have access to the data and resources that they need to do their job and nothing more. If domain admin access is required, it should be provided on a temporary basis as and when needed.
The Domain Administrator account is generally only required for setting up the domain and for emergencies, such as disaster recovery. The account should not really be used for any other purpose and the credentials for this account should be stored securely.
One common attack method for Active Directory is to take advantage of the Local Administrator account password. The Local Administrator account is often configured with the same password across domains and the same SID across installations.
Maintain an Up to Date Active Directory
All the software on your system should be up to date to ensure that known vulnerabilities have been patched. Attackers often take advantage of these known vulnerabilities, so regular patching can help minimize this risk.
Maintain a Policy of Least Privilege
As we previously touched on, you need to ensure that your users only have access to the data and resources that they need to do their job. This is known as a policy of least privilege. You should act as though all of your users are potential insider threats. If everyone has elevated privileges, and you suffer a data breach, it can be incredibly difficult to investigate the source.
Insider threats are notoriously tricky to identify and remediate at the best of time. Don’t make it harder for yourself by creating users with excessive permissions.
Ensure Passwords Are Strong and Regularly Rotated
It’s a simple point, but it’s worth emphasizing. Your passwords for your Active Directory should be the strictest passwords you can come up with. Best practices suggest using passphrases of three or four different random words. Passphrases are much harder for attackers to guess than complex passwords are.
Where possible, two-factor authentication should be used, and accounts should be locked out if incorrect passwords are entered more than two or three times.
Audit Changes to Active Directory Security Groups
Having a proactive and continuous auditing strategy for your Active Directory security groups is possibly the best way to prevent security threats. Most security threats that originate through Active Directory could potentially have been prevented through better visibility into the changes being made.
With proper Active Directory auditing and monitoring, you should be able to detect anomalous user behaviour, such as a large number of failed logon attempts that could signify a potential brute force attack. Changes to privileged groups should be alerted on in real time to ensure that you can investigate the change and revert it if excessive permissions were created.
It’s also best practice to audit who has privileged access in your Active Directory and modify these permissions where appropriate.
Trying to do this manually will simply not be possible, due to the amount of manual effort required to produce the reports. Event logs will not give you the detail you need and you’ll have to sift through a lot of noise to get to what’s needed.
Fortunately, there is a better way.
How Lepide Helps Audit Active Directory Security Groups
The Lepide Active Directory Auditor (part of Lepide Data Security Platform) proactively and continuously audits changes to Active Directory security groups and alerts in real time when anomalous activity is detected. Specific threats to Active Directory security, such as account lockouts, failed logon attempts, and changes to security groups, can be detected and alerted on real time.
If you would like to see how the Lepide can help you audit Active Directory Security Groups, click here to schedule a demo today.