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How to Secure Active Directory Against Insider Threats. Insider threats can come from employees, contractors, or privileged users who misuse their access or unknowingly compromise their credentials. To counter these risks, a multi layered security approach is essential, involving technical controls, access management, user awareness, and continuous monitoring.

In this blog post, we explore effective strategies to enhance Active Directory security against these insider threats. Understanding potential risks and implementing appropriate safeguards strengthen your organization’s defences, mitigate vulnerabilities, and maintain the integrity of their AD services.

So let’s start with How to Secure Active Directory Against Insider Threats.

How to Secure Active Directory Against Insider Threats

Role Based Access Control (RBAC)

RBAC in Active Directory is a security model that assigns users specific roles based on their job functions. Each role has defined permissions, limiting access to only necessary resources. This ensures users have the minimum privileges required, enhancing security by reducing the vulnerability bandwidth.

It helps secure AD against insider threats in multiple ways, like:

  • Ensures granular access control: Defines specific roles with well defined permissions based on job responsibilities. This limits the user access to only the resources and actions necessary for their tasks. And this minimizes the potential for unauthorized access to sensitive data.
  • Adheres to the principle of least privilege: Grants users only the minimum level of access required to perform their duties. This significantly reduces the scope for damage caused by insider threats. Why? Because users don’t possess unnecessary privileges that is exploitable.
  • Facilitates dynamic assignment of roles: Allows users to be granted roles based on their current responsibilities. This reduces the risk of outdated or excessive permissions. So, when users change positions or roles within the organization, their access privileges is automatically adjusted accordingly.

  • Continuous monitoring and review: Requires periodic review of role assignments and access permissions. Helps to detect any anomalies, including unauthorized changes to roles or access rights. And this allows organizations to respond promptly to potential insider threats.

Separation Of Duties (SoD)

Next point of How to Secure Active Directory Against Insider Threats is introduce Separation of Duties. This process involves dividing critical tasks and permissions across multiple individuals, ensuring that no single user has complete control over a sensitive process or system. This practice prevents abuse of privileges, reduces the risk of errors or malicious activities, and enhances overall security.

Here’s how it helps keep insider threats from Active Directory at bay:

  • Prevents malicious intent: By dividing admin tasks, no individual has unrestricted access or authority. This hinders any malicious insider from carrying out a single action that compromises the entire AD environment.
  • Error prevention: Assigning tasks that require cross verification or approval to different individuals adds an extra layer of checks. This minimizes the chances of unintentional errors that results in data breaches or system compromise.
  • Easier detection of suspicious activities: When tasks are separated, abnormal behaviour becomes apparent. Unusual access attempts or changes outside the normal scope of duties is quickly identified, prompting further investigation.
  • Minimizing privilege abuse: Even if an insider manages to compromise one account, they won’t have unrestricted access to all critical systems and data. So, this limits the potential damage they cause.
  • Employee monitoring and deterrence: Employees are less likely to engage in malicious activities, acting as a deterrent against potential insider threats. This is because they know that their actions are subject to oversight and cross checking.

Monitor User Activity

  • Early detection of anomalies: Allows organizations to establish baselines of normal behaviour for each user. When deviations from these patterns occur — such as accessing unfamiliar resources or attempting unauthorized actions — it raises red flags. Plus, it enables prompt investigation and mitigates potential risks.
  • Real time threat response: Active monitoring provides real time visibility into user actions, allowing for immediate response to suspicious activities. If an insider threat is identified, admins promptly terminate unauthorized sessions, revoke privileges, and prevent further damage.
  • Audit trail: User activity logs serve as an audit trail that is invaluable during forensic investigations. In the event of a security incident, admins use these logs to reconstruct events, identify the source of the breach, and understand the extent of the damage.
  • Behavioural analysis: Machine learning algorithms and anomaly detection techniques are applied to user behaviour data to identify patterns that may indicate potential insider threats. This proactive approach enhances security by identifying suspicious activities before they escalate.

Keep Unsecured Devices Out

When a device connected to an AD network is compromised or unsecured, it provides an entry point or foothold for malicious actors to gain unauthorized access to the network, systems, or sensitive data. Plus, they are compromised and used as a launching pad for further attacks or as a means to exploit vulnerabilities in other connected devices or services.

These devices include the ones running outdated operating systems, unpatched software, or devices with weak or default credentials. When they join your AD environment, they are easy targets for attackers, potentially leading to unauthorized access, data breaches, or network compromise. 

So, it’s key for organizations to:

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Ensure No Privilege Escalation

If an employee’s device is compromised, an attacker leverage various techniques to escalate their privileges within Active Directory.

Once an attacker gains access to a non privileged account with elevated permissions, the consequences are severe. They misuse these privileges to manipulate user accounts, modify access permissions, or perform other unauthorized actions within the AD environment.

This leads to:

  • unauthorized access to sensitive resources
  • exposure of confidential information.
  • unauthorized modifications to critical configurations.
  • other malicious activities that seriously compromise the security and integrity of the system.

Enforce Strong Password Policies

Weak passwords are more susceptible to being guessed or cracked through automated methods like brute force attacks. Attackers systematically try different combinations of common or previously leaked passwords to gain unauthorized access to user accounts in your AD environment.

To mitigate this threat, organizations must implement strong password policies and security measures, including:

  • Enforcing password complexity requirements — minimum length, uppercase and lowercase letters, numbers, and special characters.
  • Mixing multi factor authentication (MFA) in the play to introduce an additional security layer.

Disable Inactive Accounts

Inactive (or dormant) accounts may still possess permissions and access rights, making them vulnerable to exploitation by insiders or malicious actors. When an employee’s account becomes inactive, it is crucial to promptly disable or remove it from the system.

Otherwise there is a risk of them being misused for unauthorized activities such as data exfiltration, where sensitive information is transferred out of the organization. This leads to intellectual property theft, financial losses, or even reputation damage.

Inactive accounts also pose a privilege escalation risk. Elevated privileges granted during active usage should be adjusted or removed upon inactivity.

Attackers specifically target inactive accounts with excessive privileges in the AD environment, allowing them to move stealthily within the network and evade detection.

To mitigate these risks, organizations must enforce robust identity management (timely disabling or removing inactive accounts). Moreover, regular auditing and review of user accounts’ access rights and privileges are essential to ensure that access is granted on a need to know basis. Implementing MFA and monitoring access logs for suspicious activities help to prevent misuse of inactive accounts. Combat inactive accounts using a mix of these strategies to enhance security in the Active Directory environment.

Limit Concurrent Logins

Another important part of Securing Active Directory Against Insider Threats is to limit concurrent logins. If you don’t limit concurrent logins, users share their credentials with others, allowing multiple individuals to use the same account simultaneously. This practice undermines individual accountability, makes it difficult to trace actions to specific users, and increases the risk of unauthorized access or misuse of user accounts.

In the absence of concurrent login limitations, attackers can use stolen or compromised credentials to gain simultaneous access to an account, and execute malicious activities as they desire.

Unlimited concurrent logins results in resource exhaustion within your AD environment. If a single user establishes multiple simultaneous sessions or if unauthorized users gain access, it strains system resources, impacts performance, and potentially leads to service disruptions or denial of service (DoS) situations.

Prohibit Open Access

Open access in Active Directory happens when there are inadequate access controls and restrictions in place, resulting in a broader range of users having unrestricted or elevated access within the directory.

One of the most concerning consequences of increased open access is the heightened risk of sensitive data exposure. With fewer restrictions, users may have unrestricted access to confidential information in your AD environment. This enables unauthorized individuals to easily access and exploit sensitive data, putting the organization at various security risks, and even legal consequences if regulatory compliance requirements are not met.

The measures like principle of least privilege (PoLP) and RBAC ensures that users only have the necessary permissions required for their specific roles and responsibilities, reducing the attack surface and limiting the potential impact of security incidents.

Thank you for reading How to Secure Active Directory Against Insider Threats. We shall conclude the article off.

How to Secure Active Directory Against Insider Threats Conclusion

Enforcing the principle of least privilege, implementing robust authentication mechanisms and monitoring solutions, providing better user education — each step is key to mitigating insider threats that put your AD environment at risk.

By prioritizing AD security and remaining vigilant against insider threats, organizations ensure the continued reliability, confidentiality, and availability of their critical resources — at all times.


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Anmol Nigam

Anmol Nigam

I write bespoke content for SaaS entrepreneurs and brands to help them scale organically.

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