Active Directory Security Assessment

1. Identifying Security Misconfigurations

Purpose: To detect and remediate vulnerabilities or misconfigurations in Active Directory (AD) that could be exploited by attackers.

• Why: Attackers often exploit misconfigurations or known escalation paths in AD to gain high privileges quickly. Proactively identifying and addressing these issues reduces the risk of privilege escalation.

• Technical Example:

  • Use Tools to Identify Misconfigurations:

    • Leverage tools like BloodHound, PowerView, or ADRecon to analyze your AD environment from an attacker's perspective:

      • Example BloodHound setup:

        Import-Module .\SharpHound.ps1
        Invoke-BloodHound -CollectionMethod All

      • BloodHound will map relationships between users, groups, and computers, highlighting potential attack paths such as over-permissioned accounts or unprotected privileged groups.

    • Review results for common misconfigurations:

      • Overly permissive ACLs (Access Control Lists).

      • Unprotected privileged groups (e.g., Domain Admins, Enterprise Admins).

      • Excessive membership in high-privilege groups.

  • Audit Group Memberships:

    • Use PowerShell to identify excessive or unnecessary memberships in privileged groups:

      Get-ADGroupMember -Identity "Domain Admins" | Select Name, SamAccountName

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2. Eliminating Low-Hanging Fruits

Purpose: To remove easy attack vectors that could allow attackers to escalate privileges with minimal effort.

• Why: Attackers often rely on simple misconfigurations or overlooked vulnerabilities to escalate privileges. Removing these "low-hanging fruits" forces attackers to use more complex techniques, increasing the likelihood of detection.

• Technical Example:

  • Disable Unused Accounts:

    • Identify and disable inactive accounts using PowerShell:

      Search-ADAccount -AccountInactive -TimeSpan 90.00:00:00 | Disable-ADAccount

    • This prevents attackers from exploiting forgotten or stale accounts.

  • Restrict Kerberos Delegation:

    • Audit and restrict unconstrained or constrained delegation permissions:

      Get-ADObject -Filter { msDS-AllowedToDelegateTo -like "*" } -Properties msDS-AllowedToDelegateTo

    • Remove delegation permissions unless absolutely necessary.

  • Remove Dangerous Permissions:

    • Audit and remove dangerous permissions like "GenericAll" or "WriteDACL":

      Get-ObjectAcl -SamAccountName "Domain Admins" | Where-Object { $_.ActiveDirectoryRights -match "GenericAll" }

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3. Staying Updated on Known Vulnerabilities

Purpose: To ensure that newly discovered vulnerabilities in Active Directory are addressed promptly.

• Why: New vulnerabilities in AD are frequently discovered, and attackers actively exploit them. System administrators may not always be aware of all published bugs or patches.

• Technical Example:

  • Monitor for New Vulnerabilities:

    • Subscribe to security advisories and mailing lists such as Microsoft Security Updates, CVE Details, or MITRE ATT&CK.

    • Example PowerShell script to check for missing patches:

      Get-HotFix | Where-Object { $_.InstalledOn -lt (Get-Date).AddMonths(-1) }

    • Apply critical patches immediately to mitigate known vulnerabilities.

  • Test for Known Exploits:

    • Use tools like Mimikatz or Rubeus in a controlled environment to test for common AD vulnerabilities:

      • Example Rubeus command to detect Kerberoasting opportunities:

        Rubeus.exe kerberoast

      • Remediate findings by enforcing strong service account passwords and monitoring for suspicious activity.

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4. Conducting Regular Assessments

Purpose: To ensure that Active Directory remains secure over time and adapts to evolving threats.

• Why: A one-time assessment is insufficient, as new vulnerabilities and misconfigurations can emerge over time. Regular assessments help maintain a strong security posture.

• Technical Example:

  • Automate Periodic Assessments:

    • Schedule regular scans using tools like PowerShell scripts or third-party solutions:

      $schedule = New-JobTrigger -Weekly -At "3:00 AM" -DaysOfWeek Monday
      Register-ScheduledJob -Name "AD_Security_Assessment" -FilePath "C:\Scripts\AD_Security_Check.ps1" -Trigger $schedule

    • Ensure reports are reviewed by the security team.

  • Engage Third-Party Experts:

    • If internal expertise is lacking, hire external consultants to perform thorough AD security assessments:

      • Request detailed reports and prioritize remediation efforts based on their findings.

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Conclusion

Active Directory security assessments are essential for maintaining a robust security posture. By identifying and addressing misconfigurations, eliminating low-hanging fruits, staying updated on vulnerabilities, and conducting regular assessments, organizations can significantly reduce the risk of privilege escalation and lateral movement by attackers.

These proactive measures ensure that even if an endpoint is compromised, attackers face significant barriers in escalating privileges or moving through the network. This approach not only protects critical assets but also increases the likelihood of detecting and responding to threats before they cause harm.