Attack Chain

1. Attacker gains initial local access to a system with Microsoft Defender installed. This may be achieved through existing credentials or exploitation of another vulnerability.
2. The attacker identifies a specific area within Microsoft Defender where access control is insufficiently granular.
3. The attacker crafts a malicious request or input that exploits the identified access control weakness.
4. Microsoft Defender processes the malicious request, failing to properly validate the attacker’s authorization level.
5. The attacker gains elevated privileges within the context of Microsoft Defender.
6. The attacker leverages the elevated privileges to modify Defender settings, policies, or configurations.
7. The attacker uses the modified Defender configuration to execute arbitrary code with elevated privileges on the system.
8. The attacker achieves full system compromise, potentially leading to data theft, malware installation, or denial of service.

Impact

Successful exploitation of CVE-2026-33825 allows an attacker to escalate privileges on a system running Microsoft Defender. This could allow the attacker to disable security features, install malware, steal sensitive data, or gain complete control of the affected system. Given the widespread deployment of Microsoft Defender, this vulnerability poses a significant risk to a large number of organizations and individuals.

Recommendation

• Apply the Microsoft patch for CVE-2026-33825 immediately to remediate the vulnerability (https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33825).
• Monitor process creation events for unusual processes spawned by Microsoft Defender processes (see Sigma rule below).
• Review and harden Microsoft Defender’s configuration to ensure least privilege and prevent unauthorized modifications.

Attack Chain

This threat brief focuses on the integration of security tools rather than a specific attack chain. However, the value of the integration is to defend against a variety of attack chains, a generalized example follows:

1. Initial Access: An attacker gains initial access through methods such as phishing or exploiting a vulnerability. (T1566, T1190)
2. Execution: The attacker executes malicious code on the endpoint. (T1059)
3. Persistence: The attacker establishes persistence to maintain access to the compromised system. (T1547)
4. Lateral Movement: The attacker moves laterally within the network to access additional systems. (T1021)
5. Credential Access: The attacker attempts to steal credentials to escalate privileges and access sensitive data. (T1003)
6. Data Exfiltration: The attacker exfiltrates sensitive data from the compromised systems. (T1041)
7. Impact: The attacker achieves their objective, such as data theft, system disruption, or ransomware deployment. (T1486)

Impact

The integration of Microsoft Defender with CrowdStrike Falcon Next-Gen SIEM aims to reduce the impact of successful attacks. Without unified detection, organizations may experience delayed detection, slower response times, increased operational costs, and potential data breaches. The number of potential victims and sectors targeted is broad, as this integration applies to any organization using both Microsoft Defender and CrowdStrike. Success of an attack despite these tools leads to data breaches, financial losses, and reputational damage.

Recommendation

• Deploy the Sigma rules in this brief to your SIEM and tune for your environment to detect suspicious processes indicative of post-exploitation activity.
• Investigate systems generating process creation events flagged by the rules in this brief (process_creation logging).
• Review Falcon Onum settings to ensure proper filtering and routing of Microsoft Defender telemetry to optimize data fidelity and reduce storage costs (Falcon Onum documentation).
• Utilize federated search capabilities to investigate across live, network, and archived data sources, including Falcon LogScale, ExtraHop, and Amazon S3 (Falcon Next-Gen SIEM documentation).

Attack Chain

This brief focuses on SIEM integration rather than a specific attack chain, but here’s a generalized scenario where this integration could improve detection:

1. Initial Access: An attacker gains initial access to an endpoint via phishing or exploitation of a vulnerability.
2. Execution: The attacker executes malicious code on the endpoint using a tool like PowerShell or a custom script.
3. Persistence: The attacker establishes persistence by creating a scheduled task or modifying registry keys.
4. Lateral Movement: The attacker attempts to move laterally to other systems on the network using techniques like pass-the-hash or exploiting SMB vulnerabilities.
5. Command and Control: The attacker establishes a command and control (C2) channel to communicate with the compromised system.
6. Data Exfiltration: The attacker identifies and exfiltrates sensitive data from the compromised network.
7. Impact: The attacker achieves their objective, such as data theft or ransomware deployment.

In this scenario, Microsoft Defender would detect initial malicious activity. Falcon Next-Gen SIEM would ingest and analyze Defender telemetry, correlating it with other data sources to provide a more complete picture of the attack and accelerate response.

Impact

Successful attacks can lead to data breaches, financial losses, and reputational damage. Organizations can experience slower detection and delayed response due to fragmented security systems. The integration of Microsoft Defender telemetry into Falcon Next-Gen SIEM aims to address these challenges by unifying detection, investigation, and response, without altering existing endpoint deployments. By leveraging Falcon Onum, organizations can improve data fidelity, lower infrastructure costs, and strengthen the foundation for AI-driven security operations across the entire ecosystem.

Recommendation

• Utilize Falcon Next-Gen SIEM to ingest and analyze Microsoft Defender telemetry for enhanced threat detection and response.
• Implement Falcon Onum for real-time data pipeline management to reduce noise, enrich data, and optimize data routing, as described in the overview.
• Leverage the federated search capabilities of Falcon Next-Gen SIEM to investigate across live, network, and archived data sources without costly re-ingestion.

Attack Chain

This threat brief outlines the integration of third-party EDR solutions into the CrowdStrike Falcon Next-Gen SIEM. There is not an actual attack chain to describe, but rather a product enhancement. The purpose of the integration is to increase SOC visibility. This enhancement does not represent a specific attack campaign, but rather the mitigation of potential attacks by unifying telemetry.

Impact

The successful implementation of CrowdStrike’s Falcon Next-Gen SIEM with third-party EDR support aims to reduce the time to detect and respond to threats across diverse environments. The integration seeks to break down data silos and provide a unified view of security events, potentially impacting organizations of all sizes and sectors. Without such integration, organizations may face slower detection times, increased operational costs due to data duplication, and a fragmented security posture. The specific number of organizations potentially impacted is currently not available.

Recommendation

• Leverage Falcon Onum’s real-time data pipeline capabilities to reduce noise and optimize telemetry before it reaches downstream systems, as mentioned in the overview.
• Utilize the federated search capabilities to investigate across live, network, and archived data sources, including Falcon LogScale, ExtraHop, and Amazon S3 via Athena, without costly re-ingestion or duplication.
• Explore the integration of Microsoft Defender telemetry into Falcon Next-Gen SIEM to unify detection, investigation, and response without changing endpoint deployments.

Attack Chain

Given that the document describes a product integration and not a specific attack, the attack chain below represents a theoretical scenario where the integration of Falcon Next-Gen SIEM with Microsoft Defender helps to detect and respond to an attack:

1. Initial Access: An attacker gains initial access to a system via a phishing email (T1566.001) containing a malicious attachment.
2. Execution: The user opens the attachment, executing a malicious payload that bypasses initial security measures.
3. Persistence: The malware establishes persistence by creating a scheduled task or modifying registry keys to ensure it runs after a system reboot.
4. Lateral Movement: The attacker uses compromised credentials to move laterally to other systems on the network, escalating privileges as needed.
5. Command and Control: The attacker establishes a command and control (C2) channel to remotely control the compromised systems and exfiltrate sensitive data.
6. Data Exfiltration: The attacker exfiltrates sensitive data from the compromised systems to an external server.
7. Detection & Response: Falcon Next-Gen SIEM, integrated with Microsoft Defender, detects anomalous behavior and alerts security analysts.
8. Remediation: Security analysts use Falcon Next-Gen SIEM to investigate the incident, contain the affected systems, and remediate the threat.

Impact

If the integration between Falcon Next-Gen SIEM and Microsoft Defender is not in place or is misconfigured, organizations face slower detection, delayed response, and a SOC struggling to keep pace with modern threats. This can lead to successful data breaches, financial losses, reputational damage, and regulatory fines. The integration aims to mitigate these risks by providing a unified platform for detecting, investigating, and responding to threats across heterogeneous environments.

Recommendation

• Evaluate the integration of Falcon Next-Gen SIEM with Microsoft Defender to unify detection, investigation, and response across your environment, as described in the overview.
• Leverage Falcon Onum’s real-time data pipeline capabilities to filter, enrich, and route data, reducing noise and improving the fidelity of telemetry for AI models and detection workflows, as described in the overview.
• Utilize Falcon Next-Gen SIEM’s federated search capabilities to investigate across live, network, and archived data sources without costly re-ingestion or duplication, as described in the overview.