Active Directory Cleanup: Best Practices to Keep AD Clean

Why Are Inactive Accounts a Threat to AD Security?

User accounts that have not been utilized for a considerable amount of time are considered inactive. These accounts could be a security risk for several reasons:

1. Unauthorized Access: People may target inactive accounts that are left operational and unsupervised. Sensitive systems or data may become accessible to unauthorized users if the access credentials linked to these accounts are compromised or found. What information may they access? And how might this affect your company? Malicious people, employees, or contractors may take advantage of inactive accounts to access systems and private information.
2. Data Breaches: A data breach involving inactive accounts could allow hackers to steal data, including bank records, client information, and intellectual property. As part of their phishing attacks, attackers frequently use the compromised credentials. They trick people into entering their credentials on phony websites by sending them phony emails or messages posing as reputable companies. Attackers can enter users’ accounts and carry out additional attacks if they unintentionally give their compromised login credentials.
3. Compliance Violations: Noncompliance with regulations is one of the risks to the security of Active Directory. Account management, access control, and user activity tracking may be subject to regulatory obligations, contingent on the company or sector. Legal and regulatory repercussions may result from improper inactive account management and noncompliance. Maintaining accounts may lead to violations of regulations like SOX, GDPR, or HIPAA, which could result in penalties and legal issues.
4. Contains Sensitive Data: Important personal data, including financial information, passwords, and company information, may still be present in inactive accounts. For these vulnerable accounts to be quickly identified and deactivated, they must be regularly monitored. There is a possibility of exposure and identity theft if these accounts are not correctly detected and terminated.
5. Hacker Takes Advantage: Identifying and blocking accounts that hackers have taken over and are exploiting as backdoors is another reason to monitor inactive accounts. After their initial malicious access to the company network has been eliminated, hackers can take over an inactive account and utilize this privileged access position to avoid arousing suspicions.

Signs of a Poorly Maintained Active Directory

These are some of the AD states that frequently result in Active Directory breaches and compromises.

1. Misconfiguration: The system is vulnerable to compromise when it is misconfigured. The compromise of a single machine gives the attacker a temporary base from which to begin moving laterally across the network. Which Active Directory configurations are frequently incorrect or not the best from a security perspective, which frequently results in security compromise? Domain Controllers, or the dedicated servers that contain Active Directory Domain Services, frequently have the same utilities and applications installed as members’ servers. This can lead to security flaws. These tools or apps may open unnecessary ports or service accounts. Domain Controllers may be permitted to browse the web or even utilize it often, which exposes the DC to download content from the Internet. Domain controllers should be regarded as more important and secure parts of the infrastructure than file, print, or other application servers. They shouldn’t execute unnecessary software or perform any other actions that can increase the attack surface. They shouldn’t have access to the internet. In Active Directory, high-privilege groups like the Domain Admins, Enterprise Admins, Schema Admins, and built-in Administrators groups are frequently set up with unnecessary group members. These groups should have as few members as feasible.
2. Antiquated Systems and Applications: Numerous enterprise environments continue to function on operating systems that have long been discontinued without any new patch releases or support from Microsoft or any other vendor, which is one of the leading indicators of poorly managed active directory. The best illustration of this is Windows Server 2003. Since 2015, Windows Server 2003 has been no longer supported. Surprisingly, though, there are still a lot of Windows 2003 servers operating file servers or other business-critical applications. Running older versions of Windows operating systems with Active Directory may necessitate reducing the security setup for authentication protocols and other security features to accommodate the operating systems’ limited capabilities. All these situations make Active Directory and other infrastructure extremely vulnerable to intrusions or security lapses. Since Active Directory is set up to handle the necessary legacy authentication protocols, it only takes one legacy application or legacy operating system to introduce domain or forest-wide vulnerabilities.
3. Outdated Patches: One area of IT that is viewed with contempt is patches. Patch management techniques that are poorly executed and leave loopholes in coverage are frequently the result of patching. Inconsistent patching is seen on Windows systems with outdated patches or without security upgrades installed. During some times, computers running operating systems other than Windows either rarely or never receive patches, and there are no planned maintenance periods to apply them. When network devices are put into production service, they are rarely patched with the most recent firmware in many contexts. Applications that are off-the-shelf may continue to function as business-critical programs even after the product’s support has ended or it is no longer produced or patched. When it comes to patching, domain controllers that are using Active Directory Domain Services might be overlooked. Each of these systems offers a point of entry for hackers seeking to get access to any system via a flaw that might not have been fixed to seal the security gap. The objective of an attacker is usually to go laterally across the network after gaining access to any kind of machine in the hopes of discovering a domain administrator or SQL DBA credential set.

As a vital component of enterprise IT, maintaining a clean and organized Active Directory is not just a best practice but it’s a necessity. Active Directory should be cleaned based on the below requirements:

1. Need for Security: Cluttered Active Directory can be stressful for security. Malicious actors may utilize inactive accounts, out-of-date permissions, and unused groups as entry points. In order to reduce the attack surface and eliminate inactive user accounts and superfluous groups that could be used to gain unauthorized access, regular auditing is important for security. The active directory will be cleared through permissions inspection and updating to guarantee people have access they require. Unusual activity can be more easily identified when Active Directory is kept clean.
2. For Operation Efficiency: It is among the crucial elements required for Active Directory cleanup. Maintaining a clean Active Directory is important for the organization’s overall operational effectiveness in addition to security and compliance. When the organization considers the expense, Active Directory must be cleaned. The risk of accidental privilege escalation is decreased and licensing expenses are decreased by eliminating unused accounts and permissions. It is simpler to find and fix problems with a neat and orderly Active Directory, which lowers downtime and increases service availability.
3. Compliance and Auditing Requirements: When audits and compliance checks are conducted, Active Directory should be cleaned up. In order to comply with regulations, enterprises must keep accurate and current records of user access and permissions. A disorganized Active Directory would make it difficult to achieve the standards. Cleaning Active Directory is necessary when upgrading and evaluating AD objects on a regular basis to comply with regulatory standards and prevent fines and penalties. When necessary to facilitate tracking of user access and actions and make it easier to identify accountable parties in the case of a security breach, it should be cleansed.
4. Future Developments and Extensions: As the company expands and changes, Active Directory should be cleaned. A clean Active Directory is said to provide a strong basis for upcoming enhancements and growth. It is therefore recommended that Active Directory be cleaned when transferring to a new server, cloud environment, or updating Active Directory itself to facilitate the migration process. Implementing new technologies or making adjustments to the IT environment is made easier with a neat and orderly Active Directory.

Below is the list of the some of the best practices for keeping your Active Directory clean and secure:

1. Disable Accounts for Users on Extended or Permanent Leave

There are many reasons why an employee might be on extended leave. Perhaps it is for maternity leave, or perhaps they have been furloughed due to unforeseen circumstances [cough]. It is always wise to disable their account until they return.

It’s not just hackers that we need to be concerned about. For example, if an employee is feeling disgruntled after being furloughed, they may try to access their account from home and use it for nefarious purposes.

It should also be noted that just because an account has been disabled, doesn’t mean that a hacker won’t still try to gain access to it. For example, they may try to use social engineering tactics to trick the HR department into re-enabling the account.

In addition to disabling the account, it’s often a good idea to limit the account’s access permissions before doing so. Then, when the employee returns, they can submit a request for more access when required.

If there’s a possibility that the employee will not return, their account could be moved to a separate OU for a period of time before being removed. If a user’s employment contract has been officially terminated, their account should be disabled as soon as possible.

2. Disable Built-in and Unused Admin Accounts

Administrator accounts should only be enabled when absolutely necessary. Likewise, the built-in admin accounts should only be used for setup and disaster recovery and should be disabled when not in use.

The approval process for granting access to an admin account should be well documented, and the process of enabling the accounts should be recorded. Likewise, the process for disabling admin accounts should be scheduled, automated, and recorded. Doing so will give administrators visibility into how, when, and why the accounts were used.

3. Ensure that Guest Access is Disabled

Guest accounts allow users to access the network without a password. The problem with guest accounts is that malicious actors will try to target these accounts in the hope that they can gain elevated privileges, through some means or another.

It’s a good idea to disable all guest accounts by default and rename them. Admins need to ensure that any necessary guest user accounts are deleted, and those that are necessary are assigned the least privileges they need to serve their purpose.

Admins must also ensure that guest users are not allowed to invite other users to the network.

4. Remove All Inactive User Accounts

Attackers often seek to compromise inactive user accounts as these accounts are rarely monitored, largely because security teams are often not aware that they exist. It is crucially important that you are able to identify and remove inactive user accounts in a timely manner.

These days, most sophisticated real-time auditing solutions have built-in features that can detect and manage inactive user accounts.

They typically work by checking the LastLogonTimeStamp attribute, in addition to other factors such as the creation date, the last logon date, and last password reset date, to determine if the account is still relevant.

5. Clean-up User Groups and Organizational Units

Active Directory groups are typically used to assign access rights to groups of users, whereas OUs act as containers for users, groups, and computers.

In some cases, groups and OUs are empty, yet still remain active in the system, thus creating a potential security risk. Security teams will need to ensure that they can identify and remove stale user groups and OUs in a timely manner.

Before removing any OUs, you must check that it doesn’t contain any children. If you’re not 100% sure if the group or OU is going to be used again, you can convert them to a distribution group, and move them to a secure container. That way you can restore them if necessary.

6. Deal with Accounts with Expired Passwords:

Cleanup administrators should check for expired passwords and Active Directory user accounts in addition to disabled and dormant accounts. To protect data, administrators usually configure passwords and accounts to expire after a predetermined amount of time. However, passwords and user accounts frequently expire without the administrators being notified, thus they need to be reset. User logins and passwords that have expired frequently indicate that an account has been dormant for a long time. The account might still be in use, though, and administrators should be aware that expired accounts are not the same as inactive ones. To make sure that expired passwords or accounts haven’t been used before being deleted, administrators should do additional checks when looking for expired passwords. Before deleting any organizational data, administrators should make a backup, just like with disabled accounts.

How does Lepide help?

Lepide Active Directory Cleanup is a comprehensive solution that disables and moves dormant accounts to other OUs, resets passwords, and makes it easier to delete obsolete accounts in Active Directory. The AD Cleanup dashboard provides a comprehensive overview of all inactive users and computers across the network. 

Lepide tracks user behavior using machine learning techniques, giving you a general idea of the usage trends connected to certain users, groups, machines, and OUs. Inactive user accounts may be found and managed, AD cleanup operations can be scheduled, and more with certain Active Directory Cleanup solutions.

Set up a demo with one of our engineers or download the Free Trial to learn how the our Lepide Active Directory Cleanup solution may assist you in cleaning and safeguarding your Active Directory.