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Most SMB breaches start with email
Phishing and business email compromise (BEC) are the dominant initial-access vectors against mid-market companies. A single weak account is enough.
Service · Microsoft 365 Security
Microsoft 365 Security for small and mid-sized businesses.
Most SMB breaches start with email. We harden Microsoft 365 against the attacks that actually reach mid-market companies: business email compromise, credential theft, mailbox-forwarding-rule exfiltration, and unmanaged personal devices. The tenant stays friendly enough that your users won't file rebellion tickets.
By Stefan Efros, CEO & Founder, EFROSReviewed by Daniel Agrici, Chief Security Officer, EFROS
Reviewed by CSO ·
Where the real risk lives.
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Default settings are not hardened
Microsoft 365 ships with sensible defaults for usability, not for resisting a determined attacker. MFA is not on for every account out of the box.
03
Conditional Access is unscoped
Without policies tied to risk signals, sign-ins from anywhere with the right password succeed. Attackers know this.
04
Mailbox forwarding rules are unmonitored
A common BEC step: attacker sets a forwarding rule on a compromised mailbox to read replies for weeks. No one notices unless someone is watching.
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SPF / DKIM / DMARC fail open
Most domains have at least one of the three misconfigured. Attackers spoof the domain externally; your tenant accepts internal-looking phish.
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Devices are unmanaged
Personal laptops and unmanaged phones touching corporate Microsoft 365 with no compliance enforcement. One ransomware run away from a tenant-wide blast.
What's included.
Delivered under the Secure Operations or Fortress SOC tier. License-tier dependent (Microsoft 365 Business Premium covers most; E5 unlocks the full Defender XDR stack):
- CIS Microsoft 365 Foundations Benchmark baseline
- Conditional Access policies (location, device, risk-based)
- Identity Protection (sign-in risk + user risk policies)
- Microsoft Defender for Office 365 (Safe Links, Safe Attachments, anti-phish)
- Microsoft Defender for Endpoint (EDR + ASR rules)
- Microsoft Defender for Cloud Apps (CASB + shadow-IT visibility)
- Intune device management (Windows, macOS, iOS, Android)
- Data Loss Prevention (DLP) policies on email + SharePoint + OneDrive
- SPF, DKIM, DMARC alignment + DMARC reporting
- Mailbox audit logging + forwarding-rule monitoring
- Privileged Identity Management (PIM) for admin roles
- Quarterly security posture review against CIS + Microsoft Secure Score
Why EFROS for Microsoft 365.
Our engineers hold individual Microsoft certifications that map directly to this work — including Microsoft 365 Enterprise Administrator Expert, Microsoft Identity and Access Administrator, and Defender / Sentinel specializations. Specific credentials and vendor partnership letters are documented and provided under NDA via the Trust Center. We configure the tenant the way Microsoft's own security architects would, and we keep operating it afterwards. Plenty of MSPs will stand it up and hand it back. We don't do that.
Your configuration lives in version control. Conditional Access policies, DLP rules, Defender configurations — all of it. The day you leave us (it happens, occasionally), you take a clean tenant and the as-built docs with you. No vendor lock, no re-discovery, no surprises for whoever picks it up.
Frequently asked.
Do you replace Microsoft 365 with something else?
No. We harden your existing Microsoft 365 tenant. The licensing, the data, and the user experience stay the same. Configuration, policies, and detection content change.
Which Microsoft 365 license tier do we need?
Microsoft 365 Business Premium covers most of what we deploy on the Secure Operations tier. Microsoft 365 E5 unlocks the full Defender XDR + Sentinel stack used at the Fortress SOC tier.
Will users feel the change?
Mostly through MFA prompts and Conditional Access. We schedule the rollout, train end users, and run the first 30 days with extra support to keep helpdesk volume manageable.
Do you handle the migration if we're still on Google Workspace?
Yes. We do greenfield Microsoft 365 deployments and Google-Workspace-to-Microsoft-365 migrations under the same engagement. Mailboxes, files, identity, and devices.
Can you support hybrid identity with on-premise Active Directory?
Yes. Entra Connect, password hash sync or pass-through authentication, hybrid Conditional Access, and on-prem device join — all supported.