How to Leverage CrowdStrike and Microsoft Integration for Unified Defense

The cybersecurity landscape has just shifted significantly. For years, CrowdStrike and Microsoft have been viewed as fierce competitors in the endpoint security space. However, recent developments show a thawing of this rivalry, driven by a shared goal: better defense for customers.

CrowdStrike has announced that its Next-Gen SIEM, Falcon LogScale, can now ingest Microsoft Defender for Endpoint telemetry. This move is a win for security operations centers (SOCs) everywhere, reducing tool fatigue and increasing visibility. For defenders, this means you no longer have to choose sides blindly; you can leverage the strengths of both ecosystems to create a more resilient defense posture.

Introduction: The Shift Toward Interoperability

For IT and security teams, the "vendor wars" have often led to siloed data. If your organization standardized on Microsoft 365 but used CrowdStrike for specialized threat hunting, correlating data between the two was historically difficult. This integration addresses that gap directly. By allowing CrowdStrike's SIEM to natively ingest Microsoft Defender telemetry, defenders gain a unified view of endpoint data without complex, custom middleware.

This matters because modern attacks are fast and sophisticated. Relying on a single source of truth or struggling to normalize logs from incompatible vendors delays detection and response. This collaboration ensures that defenders can focus on stopping threats rather than troubleshooting data pipelines.

Technical Analysis: The Integration Architecture

The core of this news is the technical capability to stream Microsoft Defender for Endpoint (MDE) telemetry into CrowdStrike Falcon LogScale.

Affected Products/Systems:

• Microsoft Defender for Endpoint (MDE): The source of the telemetry, including process creation, network connections, and alert data.
• CrowdStrike Falcon LogScale (Next-Gen SIEM): The ingestion and analytics platform.

Technical Implications: Previously, organizations had to rely on Microsoft Sentinel or third-party connectors to route MDE data to external SIEMs. This direct ingestion implies a more optimized data flow. From a defensive perspective, this allows security teams to apply CrowdStrike's high-performance indexing and query capabilities to Microsoft's rich endpoint data.

Severity & Relevance: While this is not a vulnerability (CVE), it is a critical upgrade in defensive infrastructure. The ability to correlate CrowdStrike's telemetry (which is often lightweight and behavioral) with Microsoft's deep OS integration telemetry provides a higher fidelity of detection, reducing false positives and catching sophisticated "living off the land" attacks that might evade a single vendor.

Executive Takeaways

1. Breakdown of Silos: The rivalry between CrowdStrike and Microsoft is cooling, paving the way for multi-vendor defense strategies that were previously cumbersome.
2. Optimized ROI: Organizations can retain investments in the Microsoft E5 stack while utilizing CrowdStrike's advanced SIEM capabilities without paying double for data ingress or struggling with API limits.
3. Improved Detection Logic: Correlating data from two distinct detection engines increases the likelihood of identifying novel threats and evasion techniques.

Defensive Monitoring

To protect your organization effectively, whether you are using Microsoft Defender, CrowdStrike, or both, you must monitor for attempts to evade or disable these security controls. The following detection rules and queries help ensure the integrity of your defenses.

SIGMA Detection Rules

The following SIGMA rules detect attempts to disable or interfere with Microsoft Defender, a common tactic used by attackers to evade detection. These are relevant because ingesting this telemetry into CrowdStrike allows for high-performance hunting of these specific evasion behaviors.

---
title: Tampering with Microsoft Defender Service
id: a1b2c3d4-5e6f-4a3b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects attempts to stop, disable, or delete the Microsoft Defender service or configuration using sc.exe or PowerShell.
references:
  - https://attack.mitre.org/techniques/T1562/001/
author: Security Arsenal
date: 2024/05/21
tags:
  - attack.defense_evasion
  - attack.t1562.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_sc:
    Image|endswith: '\sc.exe'
    CommandLine|contains:
      - 'stop'
      - 'delete'
      - 'disable'
    CommandLine|contains:
      - 'WinDefend'
      - 'Sense'
  selection_powershell:
    Image|endswith: '\powershell.exe'
    CommandLine|contains:
      - 'Set-MpPreference'
      - 'DisableRealtimeMonitoring'
      - 'Add-MpPreference'
  condition: 1 of selection*
falsepositives:
  - Legitimate system administration or IT maintenance scripts
level: high
---
title: Suspicous Clearing of Windows Event Logs
id: b2c3d4e5-6f7a-5b4c-9d0e-1f2a3b4c5d6e
status: experimental
description: Detects attempts to clear Windows event logs, which is a common anti-forensics technique used by attackers to hide telemetry.
references:
  - https://attack.mitre.org/techniques/T1070/001/
author: Security Arsenal
date: 2024/05/21
tags:
  - attack.defense_evasion
  - attack.t1070.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_wevtutil:
    Image|endswith: '\wevtutil.exe'
    CommandLine|contains: 'cl'
  selection_powershell:
    Image|endswith: '\powershell.exe'
    CommandLine|contains:
      - 'Clear-EventLog'
      - 'Remove-EventLog'
  condition: 1 of selection*
falsepositives:
  - System administrators performing log maintenance
level: medium

KQL Queries (Microsoft Sentinel/Defender)

These KQL queries are designed to be run in Microsoft Sentinel or the Defender portal. They verify the status of Defender and look for tampering events. If you are ingesting this data into CrowdStrike, similar logic applies for hunting.

// Hunt for registry modifications that disable Defender features
DeviceRegistryEvents
| where RegistryKey contains @"Microsoft\Windows Defender\Features"
| where ActionType == "RegistryValueSet"
| project Timestamp, DeviceName, RegistryKey, RegistryValueName, RegistryValueData, InitiatingProcessFileName, InitiatingProcessAccountName
| order by Timestamp desc


// Check for service configuration changes targeting WinDefend
DeviceEvents
| where ActionType == "ServiceConfigurationChange"
| where ServiceName contains "WinDefend"
| project Timestamp, DeviceName, ServiceName, ServiceConfigurationChangeType, InitiatingProcessFileName, InitiatingProcessAccountName
| order by Timestamp desc

Velociraptor VQL

Velociraptor is a powerful tool for endpoint hunting. Use these artifacts to hunt for persistence mechanisms or configurations that disable security tools on your endpoints.

-- Hunt for registry keys that disable real-time protection in Windows Defender
SELECT 
  Timestamp,
  Key.Path AS RegistryPath,
  Key.Name AS KeyName,
  Data.value AS Value,
  Data.type AS ValueType
FROM read_reg_key(globs="HKLM\SOFTWARE\Microsoft\Windows Defender\Features\*")
WHERE Data.value != 1 AND Name =~ "Disable"

-- Hunt for suspicious scheduled tasks that might be clearing logs
SELECT 
  Name,
  Action,
  Trigger,
  Command,
  Author
FROM glob(globs="C:\Windows\System32\Tasks\*")
WHERE read_file(filename=OSPath) =~ "wevtutil" OR read_file(filename=OSPath) =~ "Clear-EventLog"

PowerShell Remediation Script

If you suspect tampering has occurred, use the following PowerShell script to restore Microsoft Defender to its secure baseline configuration.

<#
.SYNOPSIS
    Restores Microsoft Defender real-time protection and basic settings.
.DESCRIPTION
    This script re-enables critical Defender components that may have been disabled by an attacker or misconfiguration.
#>

Write-Host "Checking Windows Defender Status..." -ForegroundColor Cyan

# Set-MpPreference to disable IOAV protection (often targeted)
Set-MpPreference -DisableIOAVProtection $false -ErrorAction SilentlyContinue

# Re-enable Real-time Monitoring
Set-MpPreference -DisableRealtimeMonitoring $false -ErrorAction SilentlyContinue

# Re-enable Behavior Monitoring
Set-MpPreference -DisableBehaviorMonitoring $false -ErrorAction SilentlyContinue

# Re-enable Script Scanning
Set-MpPreference -DisableScriptScanning $false -ErrorAction SilentlyContinue

# Ensure WinDefend Service is running
$serviceName = "WinDefend"
$service = Get-Service -Name $serviceName -ErrorAction SilentlyContinue
if ($service.Status -ne "Running") {
    Write-Host "Starting $serviceName..." -ForegroundColor Yellow
    Start-Service -Name $serviceName -ErrorAction SilentlyContinue
}

Write-Host "Remediation actions completed." -ForegroundColor Green

Remediation: Strengthening the Defense Posture

With this new integration available, organizations should take the following steps to maximize their defensive capabilities:

1. Update Ingestion Pipelines: Work with your SOC engineering team to configure the CrowdStrike Falcon LogScale connector for Microsoft Defender. Ensure you are ingesting high-value event schemas, specifically DeviceProcessEvents, DeviceNetworkEvents, and DeviceRegistryEvents.
2. Review False Positive Logic: Since you will be correlating data from two vendors, you may encounter duplicate alerts. Establish a deduplication rule in your SIEM where a CrowdStrike alert takes precedence or suppresses the equivalent Microsoft alert to reduce analyst fatigue.
3. Validate Agent Health: Ensure that both the CrowdStrike Falcon Sensor and the Microsoft Defender agent are running correctly on all endpoints. Velociraptor or SCCM queries can be used to audit agent deployment status.
4. Hunt for Evasion: Use the SIGMA rules and VQL provided above to proactively hunt for signs that attackers are trying to disable these tools before the integration is fully live.

Related Resources

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