Why Hackers Love Microsoft 365

Microsoft 365 is the crown jewel for attackers

Microsoft 365 has become the backbone of modern business. For small and mid-sized organizations, it powers everything from email and file storage to authentication, collaboration, and business continuity.

That also makes it one of the most targeted platforms on the internet. Compromising a Microsoft 365 account can mean access to sensitive data, client communications, financial records, and administrative controls.

Did you know? Over 345 million people use Microsoft 365 globally, and nearly 90 percent of cyberattacks begin with email or identity compromise.

Most tenants are still exposed

Here are the most common exposures we see:

• Legacy authentication is still enabled, allowing attackers to bypass MFA entirely
• Admin accounts lack MFA, even when those accounts can reset passwords
• Audit logging is turned off, which means no trail to follow after an incident
• External sharing is unrestricted, making it easy for data to leak out
• Auto-forwarding rules silently send emails to attacker-controlled mailboxes

A real baseline has finally arrived

CISA released ScubaGear — a tactical, credible security baseline for Microsoft 365. It includes:

• A detailed configuration checklist
• A scoring system from 0 to 100
• A free PowerShell script to run assessments
• JSON output you can integrate or report on