Code integrity device policy

Code Integrity is a security feature that ensures only trusted and verified code runs on a device. This policy is commonly implemented in enterprise environments, secure systems, and modern operating systems like Windows (via Windows Defender Application Control (WDAC) and Hypervisor-Protected Code Integrity (HVCI)).

1. Purpose of Code Integrity Policy

?? Prevent execution of untrusted, tampered, or malicious code. ?? Ensure compliance with security standards. ?? Protect critical system files and applications from modification. ?? Reduce the risk of malware infections and unauthorized changes.

2. Key Components of Code Integrity Policies

?? Secure Boot & Trusted Boot

• Ensures only signed and verified firmware & OS components load during startup.

?? Hypervisor-Protected Code Integrity (HVCI)

• Uses virtualization to protect kernel-level code from tampering.

?? Windows Defender Application Control (WDAC)

• Allows only pre-approved applications and scripts to run.

?? Driver Signing Enforcement

• Blocks unsigned or unauthorized kernel-mode drivers.

?? Software Restriction Policies (SRP) or AppLocker

• Restricts execution of non-trusted software.

3. Implementation Steps for Code Integrity Policy

Step 1: Define Security Requirements

• Identify critical applications that must be allowed or blocked.
• Set policies for software updates, patches, and driver installations.

Step 2: Enable Windows Defender Application Control (WDAC)

• Use Group Policy or MDM (Microsoft Intune) to enforce WDAC rules.
• Configure policies using allowlists or deny lists.

Step 3: Enforce Hypervisor-Protected Code Integrity (HVCI)

• Enable HVCI via Group Policy or Windows Security settings.
• Ensure hardware virtualization is supported and enabled in BIOS.

Step 4: Implement Secure Boot & Driver Signing Enforcement

• Enable Secure Boot in BIOS settings.
• Restrict the installation of unsigned drivers and enforce Microsoft-signed drivers only.

Step 5: Monitor & Audit Code Execution

• Use Event Viewer, Microsoft Defender ATP, or SIEM tools to track violations.
• Set up alerts for unauthorized software execution attempts.

4. Best Practices for Code Integrity Policies

? Regularly update policies to include new trusted applications. ? Use Application Control solutions like Microsoft Defender, Carbon Black, or CrowdStrike. ? Enable logging & auditing to detect and respond to security threats. ? Educate users about phishing & malware risks to prevent unauthorized software installations.

5. Challenges & Limitations

?? Performance Impact – Some legacy applications may not be compatible. ?? False Positives – Strict policies may block legitimate applications. ?? Management Complexity – Requires continuous updates & monitoring.

Conclusion

Implementing a Code Integrity Policy strengthens device security by ensuring only verified and trusted code runs. This reduces malware risks, enhances compliance, and improves overall system integrity.