CIS Windows 11 Compliance Hardening

Engagement Overview

Cybernerds was engaged to assess and remediate CIS compliance across a multinational financial services firm with offices in Taiwan and Malaysia. The engagement began with IRIS to baseline the current security posture, followed by PDS implementation to design, deploy, and validate CIS Level 1 hardening across the entire Windows endpoint estate.

Initial State

The organization's newest Windows 11 device was failing nearly 70% of CIS Level 1 security controls. Legacy Windows 10 systems showed consistent misconfiguration across both regions. Key findings included:

• ✓68.9% of CIS Level 1 controls failing on the newest Windows 11 endpoint
• ✓No password policies, audit logging, or attack surface reduction rules enforced
• ✓Inconsistent security configuration between Taiwan and Malaysia offices
• ✓Internal IT team skilled in daily operations but lacked specialized CIS and Intune hardening expertise
• ✓No baseline documentation or compliance tracking mechanism

Key Challenges — IRIS Findings

• ✓Compliance Gap: 457 CIS controls required mapping, configuration, and validation
• ✓Multi-Region: Policies needed to account for regional differences while maintaining a consistent baseline
• ✓Legacy Systems: Windows 10 devices required separate configuration profiles
• ✓Knowledge Transfer: Internal IT team needed training to maintain hardened state post-engagement
• ✓Scale: Changes needed phased rollout to avoid disrupting daily operations across two countries

Solution Design — PDS Framework

• ✓CIS Mapping: All 457 CIS Windows 11 v4.0.0 Level 1 controls mapped to Intune configuration profiles
• ✓Profile Architecture: Grouped by CIS domain — password, audit, firewall, ASR, encryption, network, user rights
• ✓Phased Deployment: Pilot group → early adopters → broad rollout per region
• ✓Compliance Monitoring: Intune compliance policies configured to report control enforcement status
• ✓Documentation: Full policy-to-control mapping workbook delivered for ongoing governance

Implementation — PDS Execution

Deployment was executed in phases across both regions, with compliance validation gates before each expansion.

• ✓Mapped all 457 CIS Level 1 controls to Intune Settings Catalog and custom OMA-URI policies
• ✓Created Intune configuration profiles organized by CIS domain
• ✓Deployed hardened baselines to pilot devices in Taiwan, validated compliance
• ✓Extended deployment to Malaysia office with region-specific validation
• ✓Configured Defender Attack Surface Reduction rules aligned with CIS recommendations
• ✓Enabled BitLocker with TPM enforcement and Intune recovery key escrow
• ✓Deployed Windows Firewall profiles matching CIS baseline requirements
• ✓Configured advanced audit logging policies for security event visibility

Validation — PDS Validation Phase

• ✓CIS Level 1 compliance confirmed across all Windows 11 endpoints in both regions
• ✓Windows 10 devices hardened with equivalent controls where applicable
• ✓BitLocker encryption active on all devices with recovery keys escrowed in Intune
• ✓ASR rules enforced and validated — no false positive disruptions in production
• ✓Audit policies generating expected security events in Windows Event Log
• ✓Firewall profiles applied and verified across both wired and wireless networks
• ✓Compliance dashboard showing real-time enforcement status per device

Outcome

• ✓Full CIS Level 1 compliance across 457 controls — from 68.9% failure to 100% enforced
• ✓Consistent security baseline across Taiwan and Malaysia offices
• ✓Complete policy-to-control mapping workbook for ongoing compliance governance
• ✓Internal IT team trained on maintaining and auditing the hardened configuration
• ✓Repeatable deployment model for new devices entering the environment
• ✓Foundation for future CIS Level 2 hardening if required