Full Report
Most Microsoft 365 environments are missing more than half of the recommended security controls, even with tooling in place. Here's why that happens and what Huntress Managed ISPM does about it.
Analysis Summary
# Best Practices: Microsoft 365 Identity Hardening
## Overview
These practices address the critical "implementation gap" in Microsoft 365 environments. Despite having security tools, many organizations fail to activate or maintain essential controls due to fear of user disruption, configuration drift, and complex licensing. These guidelines focus on preventing identity-based attacks—which account for nearly 80% of critical incidents—by hardening account privileges and MFA configurations.
## Key Recommendations
### Immediate Actions
1. **Audit Service Account Permissions:** Identify service accounts that own "Enterprise Applications." Ensure they do not have the ability to create new credentials or escalate privileges.
2. **Eliminate Standard User Admin Rights:** Disable settings that allow standard users to perform administrative functions or register high-privilege applications.
3. **Review MFA Exceptions:** Identify and remove any "temporary" MFA exceptions that were never closed.
### Short-term Improvements (1-3 months)
1. **Standardize MFA Configurations:** Move beyond basic MFA to "Recommended MFA" (e.g., FIDO2 or Phishing-resistant methods) across the entire tenant.
2. **Establish a Drift Monitoring Baseline:** Document current configurations and set a schedule (weekly or bi-weekly) to check for unauthorized changes or "silent" resets caused by Microsoft default updates.
3. **Harden Admin Accounts:** Implement strict restrictions on Global Admin accounts, ensuring they are not used for daily tasks like email or web browsing.
### Long-term Strategy (3+ months)
1. **Implement Continuous Posture Management:** Move from point-in-time audits to a managed ISPM (Identity Security Posture Management) approach to catch drift in real-time.
2. **M&A/Onboarding Security Baseline:** Develop a standardized security "template" that is applied immediately to any new tenant acquired through M&A or new client onboarding to mitigate inherited risk.
3. **Shift Left Mentality:** Integrate proactive hardening into the IT lifecycle so that security gaps are closed *before* an incident occurs, rather than relying solely on detection and response.
## Implementation Guidance
### For Small Organizations
- **Focus on Defaults:** Ensure "Security Defaults" are enabled if you lack complex licensing.
- **Minimize Admins:** Keep Global Admins to a maximum of 2-4 people to reduce the attack surface.
### For Medium Organizations
- **Conditional Access:** Transition from Security Defaults to Conditional Access policies to allow for more granular control without breaking workflows.
- **Documentation:** Maintain a strict log of why exceptions exist and set expiration dates for every exception.
### For Large Enterprises
- **Automated Enforcement:** Use tools to automatically revert configuration drift.
- **Privileged Identity Management (PIM):** Implement "Just-In-Time" access so accounts only have admin rights when actively performing a task.
## Configuration Examples
- **Application Registration:** Disable `Users can register applications` in Entra ID (formerly Azure AD) settings to prevent users from creating service principals that could be exploited for escalation.
- **Consent Settings:** Configure `User consent settings` to "Do not allow user consent" for apps requesting access to data, requiring admin review instead.
## Compliance Alignment
- **NIST SP 800-171:** Proper ISPM implementation can cover up to 55 of the 110 requirements.
- **CMMC (Cybersecurity Maturity Model Certification):** Essential for maintaining eligibility for DAF (Department of the Air Force) and other DoD contracts.
- **CIS Microsoft 365 Foundations Benchmark:** Aligns with core identity and access control recommendations.
## Common Pitfalls to Avoid
- **"Policy in Draft" Syndrome:** Letting critical security policies sit in "Report-only" mode indefinitely due to fear of user complaints.
- **Ignoring Managed Service Provider (MSP) Drift:** Assuming a setting stays "fixed" once an MSP sets it; licensing changes or Microsoft updates often reset these values.
- **The "Admin-for-a-Day" Trap:** Granting high-level permissions to solve a one-time technical issue and failing to revoke them afterward.
## Resources
- **Huntress Managed ISPM:** `hXXps://www.huntress[.]com/platform/managed-ispm`
- **NIST SP 800-171 Compliance Guide:** `hXXps://www.huntress[.]com/blog/huntress-managed-ispm-cmmc-compliance`
- **Microsoft Entra ID Security Best Practices:** `hXXps://learn.microsoft[.]com/en-us/entra/fundamentals/security-operations-introduction`