80 controls · 14 categories

Microsoft 365 Security Hardening Checklist

A default Microsoft 365 tenant leaves dozens of doors unlocked. This checklist walks through 80 CIS-based controls across 13 security domains — from MFA and Conditional Access to email security, SharePoint, Teams, and Secure Score — each prioritized so you fix the highest-impact gaps first.

One-time purchase · instant download · 80 controls with verification & remediation steps

What's inside

80 controls across 14 categories

Every control is plain-language, prioritized by severity, and paired with how to verify it and how to fix it. Organized into 13 sections.

Email11
Admin Accounts8
Endpoint8
Conditional Access7
MFA6
SharePoint6
Logging6
Guest Access5
App Security5
Compliance5
Secure Score4
Passwords4
Teams4
OneDrive1

Real sample controls

A look at the highest-severity controls

These are taken directly from the checklist — no paraphrasing.

  • M365-01CRITICALMFA

    Require multi-factor authentication for every user, not just admins.

  • M365-02CRITICALMFA

    Enforce MFA on all Global Administrator accounts.

  • M365-03CRITICALMFA

    Block legacy (Basic) authentication protocols with Conditional Access.

  • M365-07CRITICALConditional Access

    Run an active Conditional Access policy that requires MFA for all users.

M365 Security Hardening Checklist

$97one-time
  • 80 prioritized controls
  • Verify & fix steps for each control
  • 14 categories across 13 sections
  • Instant download · lifetime access
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Download a free one-page preview of this checklist — the highest-impact controls, no email gate. Want the curated top-10 by email instead? Use the form on the homepage.

Why teams use Strondex

Built by security professionals

Controls drawn from CIS benchmarks, framework requirements, and real-world assessment findings.

Self-serve, no consultant

Plain-language steps you can action yourself — without the $300/hr engagement.

Honest scope

Exactly 80 controls. No inflated counts, no fabricated reviews — see the samples above.

Frequently asked questions

Is this M365 hardening checklist based on CIS benchmarks?

Yes. The 80 controls are built on CIS Microsoft 365 benchmark guidance and organized into 13 practical security domains so you can work through them tenant by tenant.

Do I need Microsoft 365 E5 to apply these controls?

Most controls apply to standard Business and E3 tenants. A handful of advanced controls (such as certain Defender and compliance features) call out the licensing they require so you know what is in scope.

Will hardening break my users’ workflows?

Each control includes verification and remediation guidance so you can roll changes out safely. The checklist flags severity so you can sequence high-impact, low-disruption changes first.