configuring-windows-defender-advanced-settings

配置 Windows Defender 高级设置

使用场景

在以下情况下使用此技能：

• 为增强防护而配置 Microsoft Defender for Endpoint (MDE) 的默认设置之外的选项
• 实施攻击面缩减 (ASR) 规则以阻止常见攻击技术
• 启用受控文件夹访问以防御勒索软件
• 配置网络保护和漏洞利用防护功能
• 在企业规模下通过 Intune、SCCM 或组策略部署 Defender 设置

不要使用此技能来部署第三方 EDR（CrowdStrike、SentinelOne），也不要用于 Microsoft Defender for Cloud（Azure 工作负载保护）。

前提条件

• 已启用 Microsoft Defender Antivirus 的 Windows 10/11 企业版
• Microsoft 365 E5 或 Microsoft Defender for Endpoint Plan 2 许可证（以使用完整的 MDE 功能）
• 用于企业策略部署的 Microsoft Intune 或 SCCM
• Microsoft 365 Defender 门户访问权限 (security.microsoft.com)
• 终结点未以活动模式运行第三方 AV（否则 Defender 会进入被动模式）

工作流

步骤 1：配置攻击面缩减 (ASR) 规则

ASR 规则可阻止恶意软件和攻击者常用的特定行为：

# Enable ASR rules via PowerShell (or deploy via Intune/GPO)
# Mode: 0=Disabled, 1=Block, 2=Audit, 6=Warn

# Block executable content from email client and webmail
Set-MpPreference -AttackSurfaceReductionRules_Ids BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550 `
  -AttackSurfaceReductionRules_Actions 1

# Block all Office applications from creating child processes
Set-MpPreference -AttackSurfaceReductionRules_Ids D4F940AB-401B-4EFC-AADC-AD5F3C50688A `
  -AttackSurfaceReductionRules_Actions 1

# Block Office applications from creating executable content
Set-MpPreference -AttackSurfaceReductionRules_Ids 3B576869-A4EC-4529-8536-B80A7769E899 `
  -AttackSurfaceReductionRules_Actions 1

# Block Office applications from injecting code into other processes
Set-MpPreference -AttackSurfaceReductionRules_Ids 75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84 `
  -AttackSurfaceReductionRules_Actions 1

# Block JavaScript or VBScript from launching downloaded executable content
Set-MpPreference -AttackSurfaceReductionRules_Ids D3E037E1-3EB8-44C8-A917-57927947596D `
  -AttackSurfaceReductionRules_Actions 1

# Block execution of potentially obfuscated scripts
Set-MpPreference -AttackSurfaceReductionRules_Ids 5BEB7EFE-FD9A-4556-801D-275E5FFC04CC `
  -AttackSurfaceReductionRules_Actions 1

# Block Win32 API calls from Office macros
Set-MpPreference -AttackSurfaceReductionRules_Ids 92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B `
  -AttackSurfaceReductionRules_Actions 1

# Block credential stealing from Windows LSASS
Set-MpPreference -AttackSurfaceReductionRules_Ids 9E6C4E1F-7D60-472F-BA1A-A39EF669E4B2 `
  -AttackSurfaceReductionRules_Actions 1

# Block process creations from PSExec and WMI commands
Set-MpPreference -AttackSurfaceReductionRules_Ids D1E49AAC-8F56-4280-B9BA-993A6D77406C `
  -AttackSurfaceReductionRules_Actions 1

# Block untrusted and unsigned processes from USB
Set-MpPreference -AttackSurfaceReductionRules_Ids B2B3F03D-6A65-4F7B-A9C7-1C7EF74A9BA4 `
  -AttackSurfaceReductionRules_Actions 1

# Block persistence through WMI event subscription
Set-MpPreference -AttackSurfaceReductionRules_Ids E6DB77E5-3DF2-4CF1-B95A-636979351E5B `
  -AttackSurfaceReductionRules_Actions 1

# Block abuse of exploited vulnerable signed drivers
Set-MpPreference -AttackSurfaceReductionRules_Ids 56A863A9-875E-4185-98A7-B882C64B5CE5 `
  -AttackSurfaceReductionRules_Actions 1

步骤 2：配置受控文件夹访问（勒索软件防护）

# Enable Controlled Folder Access
Set-MpPreference -EnableControlledFolderAccess Enabled

# Default protected folders: Documents, Pictures, Videos, Music, Desktop, Favorites
# Add custom protected folders
Add-MpPreference -ControlledFolderAccessProtectedFolders "C:\CriticalData"
Add-MpPreference -ControlledFolderAccessProtectedFolders "D:\SharedDrives"

# Allow specific applications to access protected folders
Add-MpPreference -ControlledFolderAccessAllowedApplications "C:\Program Files\CustomApp\app.exe"
Add-MpPreference -ControlledFolderAccessAllowedApplications "C:\Program Files\Backup\backup.exe"

# Set to Audit mode first to identify legitimate applications that need access
Set-MpPreference -EnableControlledFolderAccess AuditMode
# Event ID 1124 in Microsoft-Windows-Windows Defender/Operational log

步骤 3：配置网络保护

# Enable Network Protection (blocks connections to malicious domains/IPs)
Set-MpPreference -EnableNetworkProtection Enabled

# Network Protection leverages Microsoft SmartScreen intelligence
# Blocks: phishing sites, exploit hosting domains, C2 domains, malware download URLs

# Set to Audit mode first:
Set-MpPreference -EnableNetworkProtection AuditMode
# Event Log: Microsoft-Windows-Windows Defender/Operational, Event ID 1125

# Configure Web Content Filtering (requires MDE P2 license)
# Managed via Microsoft 365 Defender portal:
# Settings → Endpoints → Web content filtering → Add policy
# Categories to block: Malware, Phishing, Adult content, High bandwidth

步骤 4：配置漏洞利用防护

# Export current exploit protection settings
Get-ProcessMitigation -RegistryConfigFilePath "C:\Defender\current_mitigations.xml"

# Configure system-level mitigations
Set-ProcessMitigation -System -Enable DEP, SEHOP, ForceRelocateImages, BottomUp

# Configure per-application mitigations
# Example: Harden Microsoft Office against exploitation
Set-ProcessMitigation -Name "WINWORD.EXE" `
  -Enable DEP, SEHOP, ForceRelocateImages, CFG, StrictHandle

Set-ProcessMitigation -Name "EXCEL.EXE" `
  -Enable DEP, SEHOP, ForceRelocateImages, CFG, StrictHandle

Set-ProcessMitigation -Name "POWERPNT.EXE" `
  -Enable DEP, SEHOP, ForceRelocateImages, CFG, StrictHandle

# Import exploit protection configuration from XML template
Set-ProcessMitigation -PolicyFilePath "C:\Defender\exploit_protection_template.xml"

步骤 5：配置云保护

# Enable cloud-delivered protection (real-time threat intelligence)
Set-MpPreference -MAPSReporting Advanced
Set-MpPreference -SubmitSamplesConsent SendAllSamples

# Enable Block at First Sight (BAFS)
# Requires: Cloud protection enabled + sample submission enabled
Set-MpPreference -DisableBlockAtFirstSeen $false

# Set cloud block timeout to maximum (60 seconds)
Set-MpPreference -CloudBlockLevel High
Set-MpPreference -CloudExtendedTimeout 50

# Enable potentially unwanted application (PUA) protection
Set-MpPreference -PUAProtection Enabled

步骤 6：配置扫描和更新设置

# Configure real-time protection
Set-MpPreference -DisableRealtimeMonitoring $false
Set-MpPreference -DisableBehaviorMonitoring $false
Set-MpPreference -DisableIOAVProtection $false
Set-MpPreference -DisableScriptScanning $false

# Configure scheduled scan
Set-MpPreference -ScanScheduleQuickScanTime 12:00:00
Set-MpPreference -ScanParameters QuickScan
Set-MpPreference -ScanScheduleDay 0  # Every day
Set-MpPreference -RemediationScheduleDay 0

# Configure signature updates
Set-MpPreference -SignatureUpdateInterval 1  # Check every hour
Set-MpPreference -SignatureFallbackOrder "MicrosoftUpdateServer|MMPC"

# Enable tamper protection (prevents unauthorized changes to Defender settings)
# Managed via Microsoft 365 Defender portal:
# Settings → Endpoints → Advanced features → Tamper Protection: On

步骤 7：通过 Intune 部署（企业）

Intune Deployment Path:
1. Endpoint Security → Attack Surface Reduction → Create Profile
   - Platform: Windows 10 and later
   - Profile: Attack surface reduction rules
   - Configure each ASR rule to Block or Audit

2. Endpoint Security → Antivirus → Create Profile
   - Microsoft Defender Antivirus
   - Configure: Cloud protection, PUA, real-time protection

3. Endpoint Security → Antivirus → Create Profile
   - Microsoft Defender Antivirus Exclusions
   - Add path/process/extension exclusions for LOB apps

4. Devices → Configuration profiles → Create profile
   - Endpoint protection → Microsoft Defender Exploit Guard
   - Configure: Controlled Folder Access, Network Protection

步骤 8：在 Microsoft 365 Defender 门户中监控

Dashboard monitoring:
1. security.microsoft.com → Reports → Endpoints
   - Device health: Protection status across fleet
   - ASR rule detections: Which rules are triggering
   - Vulnerable devices: Missing security updates

2. Threat analytics:
   - Active threat campaigns and Defender coverage
   - Recommended security actions

3. Advanced hunting (KQL):
   DeviceEvents
   | where ActionType startswith "Asr"
   | summarize Count=count() by ActionType, FileName
   | sort by Count desc

   DeviceEvents
   | where ActionType == "ControlledFolderAccessViolationBlocked"
   | project Timestamp, DeviceName, FileName, FolderPath

关键概念

术语	定义
ASR 规则	攻击面缩减规则，在终结点层面阻止特定的高风险行为
受控文件夹访问	勒索软件防护功能，阻止未经授权的应用程序修改受保护文件夹中的文件
网络保护	使用 SmartScreen 智能阻止指向低信誉或已知恶意域名的出站连接
漏洞利用防护	系统和按应用程序的内存缓解措施（DEP、ASLR、CFG），以防止漏洞利用
BAFS（首次见到即阻止）	基于云的零日防护，会在允许执行前将可疑文件留在云端进行分析
篡改防护	阻止对 Defender 安全设置的未经授权更改，即使是本地管理员也无法更改

工具与系统

• Microsoft 365 Defender 门户：security.microsoft.com，用于集中管理和报告
• Microsoft Intune：基于云的终结点管理，用于部署 Defender 策略
• PowerShell (Set-MpPreference)：本地配置 Defender 设置
• WDAC（Windows Defender 应用程序控制）：互补的应用程序控制技术
• Microsoft Defender for Endpoint API：用于自动化和自定义集成的 REST API

常见陷阱

• 立即以阻止模式启用所有 ASR 规则：某些 ASR 规则会对合法软件（Office 宏、管理员脚本）产生误报。请始终先以审核模式部署并观察 2-4 周。
• 未配置受控文件夹访问排除项：备份软件、数据库应用程序和开发工具可能会被阻止写入受保护文件夹。请主动添加排除项。
• 忽视篡改防护：没有篡改防护，恶意软件或内部人员可以通过 PowerShell 或注册表编辑禁用 Defender。请通过 M365 Defender 门户启用篡改防护。
• 将 Defender 与第三方 AV 一起运行：当存在第三方 AV 时，Defender 会进入被动模式。请确保使用的是预期的 AV 解决方案，并相应配置 Defender（如果保留第三方 AV，则使用仅 EDR 模式）。
• 忘记云连接要求：云保护和 BAFS 要求终结点能够访问 Microsoft 云服务。请验证代理/防火墙规则允许 Defender 云流量。