Active Directory security groups are used to grant users permissions to IT resources. Each security group is assigned a set of access rights, and then users are made members of the appropriate groups. Done right, this approach enables an accurate, role-based approach to user management and reduces IT workload.
Why should Security Groups Stay Secure?
Security groups should always be protected with clear security protocols because they govern user and computer access to resources that could be highly confidential, sensitive, and critical to the organization. Any oversight may result in security breaches and data theft with lasting consequences. Hence, you need to establish some best practices for using and managing security groups.
Key Best Practices
The following best practices can help you use security groups effectively.
- Use Group Nesting to Simplify Access Management
- Give each security group a unique, descriptive name
- Limit each group’s permissions to the bare minimum
- Make each user a member of only the required groups
- Track group activity and changes to security groups
- Pay attention to service accounts
- Have group owners review their groups regularly, and remove groups that are no longer needed
- Use privileged accounts only when required
- Always create a recovery plan
Use Group Nesting to Simplify Access Management.
When we talk about group nesting, we refer to making an AD group a member of another group. This strategy enables us to give permissions across domains through universal groups. It works this way:
Give each security group a unique, descriptive name.
When security groups have unclear names, or multiple groups have similar names, such as ‘Sales Group 1’ and ‘Sales Group 2’, it’s difficult to ensure that they have the correct permissions and membership. To reduce risk, establish group naming standards that ensure consistency and uniqueness.
Limit each group’s permissions to the bare minimum.
The least privilege principle is the cornerstone of security. Make sure each security group is assigned only the permissions that its members need to complete their tasks. Granting excessive permissions to a group enables any group member — or an adversary who compromises their account — to abuse those rights.
Make each user a member of only the required groups.
Never add users to groups they do not need to be a part of. Moreover, remove them promptly from groups they no longer need to belong to, such as when they change roles within the organization. For example, when users change departments, remove them from the previous department’s groups and add them to the new department’s groups. That way, each user has access only to the resources they need, which reduces your organization’s attack surface area.
Track group activity and changes to security groups.
Any improper change to the permissions or membership of a security group puts the organization at increased risk of security incidents and business disruptions. Be especially vigilant about monitoring changes to highly privileged groups like Domain Admins and Enterprise Admins.
Look out for the following to detect suspicious behavior:
- Unauthorized permission and membership changes
- Unnecessary or unusual use of admin accounts
- Failed password attempts
- Locked out accounts
- Disabled or removed antivirus software
At a minimum, log the events and regularly run reports to spot suspicious activity. Even better, use a tool that will alert you in real time to changes to critical security groups, or block those changes from happening in the first place.
Pay attention to service accounts.
A service account is a special user account created to run a particular application or service. Best practices for service accounts include the following:
- Set secure passwords.
- Do not make service accounts members of built-in privileged groups like Domain Admins.
- Enforce least privilege by granting each service account the minimum access required to accomplish its tasks.
Have group owners review their groups regularly, and remove groups that are no longer needed.
Security groups are usually set up to provide access to resources for a particular project team— but when the project is over, the group is often not deleted. By requiring group owners to regularly review their groups, you can improve security by removing groups that are no longer needed.
As a best practice, disable or delete dormant accounts after about 45 days of inactivity. Set up a system to distinguish inactive accounts from active accounts, which would help in removing inactive accounts from security groups. Hackers can easily target unused accounts since no one keeps track of the account’s activities. And if that unused account is a member of multiple security groups, the implications could be devastating.
Use privileged accounts only when required.
Accounts that are members of privileged groups should be used only for performing administrative tasks that require elevated rights. For all other tasks, admins should use their regular user accounts. This strategy reduces the risk of attackers gaining control of an account that is a member of security groups with access to sensitive systems and data.
Always create a recovery plan.
Despite keeping security intact, data breaches may happen at times due to an error. As a proactive measure, have a recovery plan in place with due attention to recovering security groups. IT teams must be trained to handle such a situation with quick and intelligent decision-making.
Simplifying Security Group Management
Netwrix GroupID can help you effectively manage your Active Directory security groups. Here are some of the ways it can help you implement the best practices described above.
- Establish and enforce standards for naming groups
- Ensure the membership of security groups is accurate
- Establish an attestation process for security groups
- Set security groups to expire automatically
- Set a default group approver
Establish and enforce standards for naming groups.
Netwrix GroupID helps you implement consistency and convention in group names with the following features:
- Group name prefixes
- Regular expressions
- Templates for naming nested groups
- Lists of blocked words
Ensure the membership of security groups is accurate.
Netwrix GroupID enables you to manage group membership with LDAP queries as an alternative to manually adding and removing users, thus ensuring that membership is always up to date.
Establish an attestation process for security groups.
Netwrix GroupID makes it easy for group owners to regularly review the attributes, membership, and permissions of their security groups, as well as whether the groups are still needed. This process helps maintain a check on groups.
Set security groups to expire automatically.
You can set an expiry date for a security group, such as a group created for a specific project. Netwrix GroupID sends an email notification to a group’s owner 30 days, 7 days and 1 day before the expiration date. If the group is not renewed, it is automatically deleted. Expired groups that have been deleted can be quickly restored if necessary.
You can easily exempt any security group from expiration, including the default security groups in Active Directory.
Set a default group approver.
You can designate a default approver for groups, who will receive expiry notifications for groups without owners.
Conclusion
Properly managing your Active Directory security groups is vital to protecting your IT systems and data. A solution like Netwrix GroupID can make it easy to implement the best practices detailed here.
