--- name: windows-hardening description: Harden Windows servers per security baselines and CIS benchmarks. Configure Group Policy, Windows Defender, and security features. Use when securing Windows Server environments. category: security risk: critical source: https://github.com/BagelHole/DevOps-Security-Agent-Skills source_repo: BagelHole/DevOps-Security-Agent-Skills source_type: community date_added: '2026-09-20' license: MIT license_source: https://github.com/BagelHole/DevOps-Security-Agent-Skills/blob/main/LICENSE compatibility: Requires the relevant security tooling (scanners, vault CLIs) and an authorized scope for any active assessment. Docs-only; helper scripts and templates not bundled. metadata: author: devops-skills version: '1.0' --- # Windows Hardening Secure Windows servers following Microsoft security baselines and CIS benchmarks. ## Prerequisites - Windows Server 2019 or later (2022 recommended) - Local Administrator or Domain Admin access - PowerShell 5.1+ (built into Windows Server) - Group Policy Management Console for domain environments - Microsoft Security Compliance Toolkit (recommended) ## Security Baseline Deployment ```powershell # Download and apply Microsoft Security Baseline # Download from: https://www.microsoft.com/en-us/download/details.aspx?id=55319 # Install Security Compliance Toolkit modules Install-Module -Name SecurityPolicyDsc -Force Install-Module -Name AuditPolicyDsc -Force Install-Module -Name PSDesiredStateConfiguration -Force # Import and apply a security baseline GPO (from Security Compliance Toolkit) # Extract the toolkit, then: Import-Module "$env:USERPROFILE\Downloads\SCT\LGPO.exe" # Apply local group policy from baseline .\LGPO.exe /g ".\GPO\{baseline-gpo-guid}" # Export current security policy for review secedit /export /cfg C:\SecurityAudit\current-policy.inf ``` ## Account Policies ```powershell # ============================================ # Password Policy Configuration # ============================================ # Set password policy via net accounts net accounts /minpwlen:14 /maxpwage:90 /minpwage:1 /uniquepw:24 # Or configure via PowerShell DSC Configuration PasswordPolicy { Import-DscResource -ModuleName SecurityPolicyDsc Node localhost { AccountPolicy PasswordPolicy { Name = "PasswordPolicy" Minimum_Password_Length = 14 Maximum_Password_Age = 90 Minimum_Password_Age = 1 Enforce_password_history = 24 Password_must_meet_complexity_requirements = "Enabled" Store_passwords_using_reversible_encryption = "Disabled" } } } # ============================================ # Account Lockout Policy # ============================================ net accounts /lockoutthreshold:5 /lockoutwindow:30 /lockoutduration:30 # ============================================ # User Account Hardening # ============================================ # Rename and disable default accounts Rename-LocalUser -Name "Administrator" -NewName "LocalAdmin" Disable-LocalUser -Name "Guest" Disable-LocalUser -Name "DefaultAccount" # Remove unnecessary local accounts $unnecessaryAccounts = Get-LocalUser | Where-Object { $_.Enabled -eq $true -and $_.Name -notin @("LocalAdmin", "SYSTEM", "NetworkService", "LocalService") } foreach ($account in $unnecessaryAccounts) { Write-Host "Review account: $($account.Name) - Last logon: $($account.LastLogon)" } # Configure Local Administrator Password Solution (LAPS) # Install LAPS module Install-WindowsFeature -Name RSAT-AD-PowerShell Import-Module AdmPwd.PS # Configure LAPS for the OU Set-AdmPwdComputerSelfPermission -OrgUnit "OU=Servers,DC=example,DC=com" Set-AdmPwdReadPasswordPermission -OrgUnit "OU=Servers,DC=example,DC=com" -AllowedPrincipals "Domain Admins" ``` ## Group Policy Security Settings ```powershell # ============================================ # User Rights Assignment (via GPO or local policy) # ============================================ # Restrict remote desktop access # Computer Configuration > Policies > Windows Settings > Security Settings > Local Policies > User Rights Assignment # "Allow log on through Remote Desktop Services" = Administrators, Remote Desktop Users # Deny log on locally for service accounts # "Deny log on locally" = Service accounts # Configure via registry (alternative to GPO) # Restrict anonymous enumeration of SAM accounts Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" ` -Name "RestrictAnonymousSAM" -Value 1 # Restrict anonymous enumeration of shares Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" ` -Name "RestrictAnonymous" -Value 1 # Do not display last user name Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" ` -Name "DontDisplayLastUserName" -Value 1 # ============================================ # Security Options # ============================================ # Disable SMBv1 (critical security hardening) Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol -NoRestart Set-SmbServerConfiguration -EnableSMB1Protocol $false -Force # Require SMB signing Set-SmbServerConfiguration -RequireSecuritySignature $true -Force Set-SmbClientConfiguration -RequireSecuritySignature $true -Force # Disable LLMNR (prevent credential theft) New-Item -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient" -Force Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient" ` -Name "EnableMulticast" -Value 0 # Disable NetBIOS over TCP/IP $adapters = Get-WmiObject Win32_NetworkAdapterConfiguration | Where-Object { $_.IPEnabled -eq $true } foreach ($adapter in $adapters) { $adapter.SetTcpipNetbios(2) # 2 = Disable } # Disable WDigest (prevent plaintext password caching) Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest" ` -Name "UseLogonCredential" -Value 0 # Enable LSA Protection Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" ` -Name "RunAsPPL" -Value 1 # Configure UAC Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" ` -Name "EnableLUA" -Value 1 Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" ` -Name "ConsentPromptBehaviorAdmin" -Value 2 Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" ` -Name "PromptOnSecureDesktop" -Value 1 ``` ## Windows Firewall Configuration ```powershell # ============================================ # Enable Windows Firewall on all profiles # ============================================ Set-NetFirewallProfile -Profile Domain,Public,Private -Enabled True # Default deny inbound, allow outbound Set-NetFirewallProfile -Profile Domain -DefaultInboundAction Block -DefaultOutboundAction Allow Set-NetFirewallProfile -Profile Public -DefaultInboundAction Block -DefaultOutboundAction Allow Set-NetFirewallProfile -Profile Private -DefaultInboundAction Block -DefaultOutboundAction Allow # Enable logging Set-NetFirewallProfile -Profile Domain -LogAllowed True -LogBlocked True ` -LogFileName "%SystemRoot%\System32\LogFiles\Firewall\pfirewall.log" ` -LogMaxSizeKilobytes 32768 # ============================================ # Inbound Rules # ============================================ # Allow RDP from management network only New-NetFirewallRule -DisplayName "Allow RDP - Management" ` -Direction Inbound -Protocol TCP -LocalPort 3389 ` -RemoteAddress 10.0.100.0/24 -Action Allow -Profile Domain # Allow WinRM from management network New-NetFirewallRule -DisplayName "Allow WinRM - Management" ` -Direction Inbound -Protocol TCP -LocalPort 5985,5986 ` -RemoteAddress 10.0.100.0/24 -Action Allow -Profile Domain # Allow ICMP from internal networks New-NetFirewallRule -DisplayName "Allow ICMP - Internal" ` -Direction Inbound -Protocol ICMPv4 -IcmpType 8 ` -RemoteAddress 10.0.0.0/8 -Action Allow # Allow specific application New-NetFirewallRule -DisplayName "Allow IIS HTTPS" ` -Direction Inbound -Protocol TCP -LocalPort 443 ` -Action Allow -Profile Domain,Private # Block all other inbound by default (already set above) # ============================================ # Outbound Rules (optional - restrict egress) # ============================================ # Allow DNS New-NetFirewallRule -DisplayName "Allow DNS" ` -Direction Outbound -Protocol UDP -RemotePort 53 ` -Action Allow # Allow HTTPS for updates New-NetFirewallRule -DisplayName "Allow HTTPS Out" ` -Direction Outbound -Protocol TCP -RemotePort 443 ` -Action Allow # Allow NTP New-NetFirewallRule -DisplayName "Allow NTP" ` -Direction Outbound -Protocol UDP -RemotePort 123 ` -Action Allow # ============================================ # Firewall Audit # ============================================ # List all enabled firewall rules Get-NetFirewallRule -Enabled True | Format-Table DisplayName, Direction, Action, Profile # Export firewall rules netsh advfirewall export "C:\SecurityAudit\firewall-rules.wfw" # Find overly permissive rules Get-NetFirewallRule -Enabled True -Direction Inbound | Where-Object { $_.RemoteAddress -eq "Any" -and $_.Action -eq "Allow" } | Format-Table DisplayName, LocalPort, RemoteAddress, Profile ``` ## Audit Policy Configuration ```powershell # ============================================ # Advanced Audit Policy # ============================================ # Account Logon auditpol /set /subcategory:"Credential Validation" /success:enable /failure:enable auditpol /set /subcategory:"Kerberos Authentication Service" /success:enable /failure:enable auditpol /set /subcategory:"Kerberos Service Ticket Operations" /success:enable /failure:enable # Account Management auditpol /set /subcategory:"Computer Account Management" /success:enable auditpol /set /subcategory:"Security Group Management" /success:enable auditpol /set /subcategory:"User Account Management" /success:enable /failure:enable # Logon/Logoff auditpol /set /subcategory:"Logon" /success:enable /failure:enable auditpol /set /subcategory:"Logoff" /success:enable auditpol /set /subcategory:"Account Lockout" /success:enable /failure:enable auditpol /set /subcategory:"Special Logon" /success:enable # Object Access auditpol /set /subcategory:"File System" /success:enable /failure:enable auditpol /set /subcategory:"Registry" /success:enable /failure:enable auditpol /set /subcategory:"SAM" /success:enable /failure:enable # Policy Change auditpol /set /subcategory:"Audit Policy Change" /success:enable /failure:enable auditpol /set /subcategory:"Authentication Policy Change" /success:enable auditpol /set /subcategory:"Authorization Policy Change" /success:enable # Privilege Use auditpol /set /subcategory:"Sensitive Privilege Use" /success:enable /failure:enable # System auditpol /set /subcategory:"Security State Change" /success:enable /failure:enable auditpol /set /subcategory:"Security System Extension" /success:enable /failure:enable auditpol /set /subcategory:"System Integrity" /success:enable /failure:enable # Verify audit policy auditpol /get /category:* # Export audit policy auditpol /backup /file:C:\SecurityAudit\audit-policy.csv # ============================================ # PowerShell Logging (Critical for forensics) # ============================================ # Enable Script Block Logging New-Item -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" -Force Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" ` -Name "EnableScriptBlockLogging" -Value 1 # Enable Module Logging New-Item -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ModuleLogging" -Force Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ModuleLogging" ` -Name "EnableModuleLogging" -Value 1 New-Item -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ModuleLogging\ModuleNames" -Force Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ModuleLogging\ModuleNames" ` -Name "*" -Value "*" # Enable Transcription Logging New-Item -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription" -Force Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription" ` -Name "EnableTranscripting" -Value 1 Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription" ` -Name "OutputDirectory" -Value "C:\PSLogs" Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\Transcription" ` -Name "EnableInvocationHeader" -Value 1 # Configure Windows Event Forwarding (WEF) for centralized logging wecutil qc /q ``` ## Windows Defender Configuration ```powershell # ============================================ # Real-time Protection # ============================================ Set-MpPreference -DisableRealtimeMonitoring $false Set-MpPreference -DisableBehaviorMonitoring $false Set-MpPreference -DisableIOAVProtection $false Set-MpPreference -DisableScriptScanning $false # ============================================ # Cloud Protection # ============================================ Set-MpPreference -MAPSReporting Advanced Set-MpPreference -SubmitSamplesConsent SendAllSamples Set-MpPreference -CloudBlockLevel High Set-MpPreference -CloudExtendedTimeout 50 # ============================================ # Scan Configuration # ============================================ Set-MpPreference -ScanScheduleDay Everyday Set-MpPreference -ScanScheduleTime 02:00:00 Set-MpPreference -ScanParameters FullScan # Quick scan daily, full scan weekly Set-MpPreference -ScanScheduleQuickScanTime 12:00:00 # Scan removable drives Set-MpPreference -DisableRemovableDriveScanning $false # Scan network files Set-MpPreference -DisableScanningNetworkFiles $false # ============================================ # Attack Surface Reduction (ASR) Rules # ============================================ # Block executable content from email and webmail Add-MpPreference -AttackSurfaceReductionRules_Ids BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550 ` -AttackSurfaceReductionRules_Actions Enabled # Block Office applications from creating child processes Add-MpPreference -AttackSurfaceReductionRules_Ids D4F940AB-401B-4EFC-AADC-AD5F3C50688A ` -AttackSurfaceReductionRules_Actions Enabled # Block credential stealing from LSASS Add-MpPreference -AttackSurfaceReductionRules_Ids 9E6C4E1F-7D60-472F-BA1A-A39EF669E4B2 ` -AttackSurfaceReductionRules_Actions Enabled # Block process creations from PSExec and WMI commands Add-MpPreference -AttackSurfaceReductionRules_Ids D1E49AAC-8F56-4280-B9BA-993A6D77406C ` -AttackSurfaceReductionRules_Actions Enabled # Block JavaScript and VBScript from launching downloaded content Add-MpPreference -AttackSurfaceReductionRules_Ids D3E037E1-3EB8-44C8-A917-57927947596D ` -AttackSurfaceReductionRules_Actions Enabled # Block Office macros from calling Win32 API Add-MpPreference -AttackSurfaceReductionRules_Ids 92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B ` -AttackSurfaceReductionRules_Actions Enabled # View ASR rule status Get-MpPreference | Select-Object -ExpandProperty AttackSurfaceReductionRules_Ids Get-MpPreference | Select-Object -ExpandProperty AttackSurfaceReductionRules_Actions # ============================================ # Exclusions (minimize these) # ============================================ # Only add exclusions when absolutely necessary and document the reason Add-MpPreference -ExclusionPath "C:\AppData\SpecificApp" # Reason: false positive on app binary # Review current exclusions Get-MpPreference | Select-Object -ExpandProperty ExclusionPath Get-MpPreference | Select-Object -ExpandProperty ExclusionProcess Get-MpPreference | Select-Object -ExpandProperty ExclusionExtension # Update definitions manually Update-MpSignature ``` ## Contents - [BitLocker Drive Encryption](references/details.md) - [Credential Guard](references/details.md) - [AppLocker Configuration](references/details.md) - [Security Audit Script](references/details.md) - [Troubleshooting](references/details.md) - [Best Practices](references/details.md) - [Related Skills](references/details.md) ## When to Use This Skill Use this skill when: - Hardening new Windows Server deployments - Implementing CIS benchmarks or Microsoft security baselines - Preparing for compliance audits (SOC2, PCI-DSS, HIPAA) - Configuring security features after a security incident - Setting up Windows Defender and advanced threat protection - Establishing Group Policy security standards for a domain ## Limitations - Apply guidance only within authorized scope; test destructive steps in non-production first. - Docs-only import: upstream scripts and templates not bundled. ### Example ```bash # Read-only first: inventory before any active step. which && --help | head -n 20 ``` > Adapted from [BagelHole/DevOps-Security-Agent-Skills](https://github.com/BagelHole/DevOps-Security-Agent-Skills) (MIT); frontmatter, When to Use/Limitations, and safety boundaries added for upstream compliance. Docs-only import: helper scripts and templates not bundled.