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Introduction:
Active Directory (AD) remains the cornerstone of identity and access management in most enterprise networks, making it a prime target for cyber adversaries. Mastering its security is not optional; it’s a critical mandate for every IT professional. This article distills key insights from industry experts to arm you with the practical knowledge needed to defend your domain.
Learning Objectives:
- Understand critical Active Directory vulnerabilities and common attack vectors.
- Learn essential commands and PowerShell scripts to audit and harden your AD environment.
- Implement effective security controls and monitoring strategies to detect and mitigate threats.
You Should Know:
1. Enumerating Domain Users for Reconnaissance
Adversaries often start with reconnaissance to map the target environment. The following PowerShell command utilizes the `ActiveDirectory` module to retrieve a list of all domain users, which can be used for both auditing and malicious purposes.
`Get-ADUser -Filter -Properties | Select-Object Name, SamAccountName, UserPrincipalName, Enabled, LastLogonDate | Export-Csv -Path “AllDomainUsers.csv” -NoTypeInformation`
Step-by-step guide:
- Ensure you have the RSAT: Active Directory Domain Services tools installed on your Windows machine or run this from a management server.
2. Open PowerShell with administrative privileges.
- Import the module with `Import-Module ActiveDirectory` (if not loaded automatically).
- Execute the command. It fetches all users, selects key properties including their last logon time and status, and exports the data to a CSV file for analysis.
- Use this output to audit for stale accounts (e.g., `Enabled -eq $True` and
LastLogonDate -lt (Get-Date).AddDays(-90)) which should be disabled to reduce the attack surface.
2. Detecting Kerberoastable Accounts
Kerberoasting is a prevalent attack where service accounts with weak passwords are targeted. This command helps identify all service accounts (User accounts with a Service Principal Name) that are potentially vulnerable.
`Get-ADUser -Filter {ServicePrincipalName -ne “$null”} -Properties ServicePrincipalName, LastLogonDate, PasswordLastSet | Where-Object {$_.Enabled -eq $True} | Select-Object Name, ServicePrincipalName, PasswordLastSet, LastLogonDate`
Step-by-step guide:
- Run the command in a PowerShell session with the AD module imported and necessary permissions.
- The cmdlet queries for all user objects that have a Service Principal Name (SPN) set, which denotes a service account.
- The output lists these accounts, allowing you to identify those with old passwords that have not been rotated recently. Focus on accounts with `PasswordLastSet` dates older than your password policy (e.g., 60-90 days). Ensure these accounts have strong, complex passwords.
3. Auditing Active Directory for Unconstrained Delegation
Unconstrained delegation is a dangerous configuration that can lead to full domain compromise if a compromised service account has it enabled. This command finds all computer and user accounts configured with unconstrained delegation.
`Get-ADObject -Filter {TrustedForDelegation -eq $True -AND objectClass -eq “computer”} -Properties TrustedForDelegation, OperatingSystem, MemberOf | Select-Object Name, OperatingSystem, MemberOf`
Step-by-step guide:
- Execute the command in your AD environment. This example focuses on computer accounts.
- Review the output carefully. Any servers, especially domain controllers (which should never have unconstrained delegation), listed here pose a significant risk.
- Mitigation involves removing the delegation setting or, more securely, transitioning to constrained or resource-based constrained delegation. This is a critical hardening step.
4. Hardening NTLM Authentication
NT Lan Manager (NTLM) is a weak authentication protocol susceptible to relay attacks. Disabling it and enforcing Kerberos is a key mitigation. This command audits the domain for NTLM usage.
`Get-ADDomainController -Filter | Select-Object Name, Domain, Forest | ForEach-Object { Get-WinEvent -LogName “Security” -ComputerName $_.Name -FilterXPath “[System[EventID=4624]] and [EventData[Data[@Name=’LmPackageName’]=’NTLM V2′]]” -MaxEvents 10 -ErrorAction SilentlyContinue } | Select-Object MachineName, TimeCreated, Properties`
Step-by-step guide:
- This advanced command queries the Security event logs on all domain controllers for successful logon events (ID 4624) that used NTLMv2.
- Analyze the results to identify clients and servers that are still relying on NTLM. This is an audit command; the output requires manual review.
- To harden the environment, configure the Group Policy “Network security: Restrict NTLM: NTLM authentication in this domain” to “Deny All” after ensuring no critical applications break. Always test in a non-production environment first.
5. Implementing LAPS for Local Administrator Password Management
The Local Administrator Password Solution (LAPS) is a free Microsoft tool that manages unique, complex passwords for local administrator accounts on domain-joined machines. After installing LAPS, use PowerShell to check its status.
`Get-ADComputer -Filter -Properties ms-Mcs-AdmPwd, ms-Mcs-AdmPwdExpirationTime | Where-Object {$_.’ms-Mcs-AdmPwd’ -ne $null} | Select-Object Name, ms-Mcs-AdmPwdExpirationTime`
Step-by-step guide:
- This command checks which computers have had a LAPS password set. The `ms-Mcs-AdmPwd` attribute stores the password (readable only by authorized users), and the expiration time attribute tracks rotation.
- If no results appear, LAPS is not deployed. Deploy LAPS by installing the client-side extension on all machines and configuring the appropriate Group Policy settings to define password length, complexity, and rotation frequency.
- Authorized personnel can then retrieve the current password for a specific computer using
Get-LAPSPassword -ComputerName "TARGETPC01".
6. Auditing Sensitive Group Memberships
Privileged groups like Domain Admins, Enterprise Admins, and Schema Admins hold keys to the kingdom. Regular auditing of their membership is non-negotiable.
`Get-ADGroupMember -Identity “Domain Admins” -Recursive | Get-ADUser -Properties LastLogonDate | Select-Object Name, SamAccountName, LastLogonDate | Sort-Object LastLogonDate`
Step-by-step guide:
- Run the command for each critical group (“Domain Admins”, “Enterprise Admins”, “Schema Admins”, “Administrators”).
- The `-Recursive` parameter ensures any nested groups are also expanded.
- Scrutinize the list. Principle of Least Privilege (PoLP) dictates that membership should be extremely limited. Any account that hasn’t logged on recently or doesn’t have a clear, ongoing need for membership should be removed immediately.
7. Leveraging Microsoft’s Attack Surface Analyzer
Beyond native commands, utilize free tools like Attack Surface Analyzer (ASA) from Microsoft to create a baseline and then scan for changes that could indicate compromise or misconfiguration.
`asa.exe scan /F BaseRun.json`
`asa.exe scan /F CompareRun.json`
`asa.exe analyze /B BaseRun.json /C CompareRun.json /R OutputReport.html`
Step-by-step guide:
- Download and install Attack Surface Analyzer on a clean, reference system.
- Perform your first scan (
asa.exe scan) to create a known-good baseline (BaseRun.json). - After a software install, configuration change, or suspected incident, run a second scan to create a comparison point (
CompareRun.json). - Generate a report (
asa.exe analyze). The HTML report (OutputReport.html) will highlight new registry keys, files, ports, services, and other changes, helping you identify potential malware or unwanted configurations.
What Undercode Say:
- Active Directory is not “set and forget.” Continuous auditing and hardening are required to maintain a secure posture against evolving threats.
- The principle of least privilege is the most effective yet most often neglected control. Rigorously enforce it on users, admins, and service accounts.
The post from a renowned Microsoft MVP highlights a critical truth: securing Active Directory is a hands-on, continuous process, not a theoretical exercise. The industry shift is towards “assume breach” mentality, where the focus is on making lateral movement and privilege escalation incredibly difficult for attackers who have already gained an initial foothold. The commands and techniques outlined here form the bedrock of this defensive strategy. They allow blue teams to move from a passive to an active defensive stance, constantly hunting for misconfigurations and weaknesses that red teams and advanced persistent threats (APTs) would inevitably exploit. Mastering these skills is no longer a niche specialty but a core competency for any cybersecurity professional operating in a Windows environment.
Prediction:
The sophistication of AD-focused attacks will continue to accelerate, leveraging AI to automate reconnaissance and identify misconfigurations at scale. Future attacks will increasingly abuse trust relationships like Azure AD Connect sync accounts and other hybrid identity components. The organizations that will successfully defend against these onslaughts are those that have embraced automation for continuous security auditing, implemented robust credential management like LAPS/Windows LAPS, and have fully decommissioned legacy protocols like NTLM. The era of manual AD security is over; the future belongs to automated, intelligent, and integrated defense-in-depth strategies.
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IT/Security Reporter URL:
Reported By: https://lnkd.in/p/dhkhRYCu – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
