The Hacker’s Perspective: Exploiting Microsoft 365 – And How You Can Stop Me

Introduction: Welcome to My World

If you’re reading this, chances are you’re on the other side of the battlefield—the defender, the security analyst, the IT admin desperately trying to keep your Microsoft 365 environment secure. Well, let me take you on a journey into my world, the world of the hacker. I’ll show you exactly how I break into Microsoft 365 tenants, elevate my privileges, persist in your environment, and—if I feel like it—exfiltrate your most sensitive data.

This isn’t fiction. This is what happens every single day to organizations like yours. The only question is: Are you prepared?

Phase 1: Reconnaissance – Spying Before Striking

Before I ever launch an attack, I need to gather intel. And trust me, you make it easy.

• LinkedIn: Employees post job descriptions revealing what security tools you use. I love when they mention “familiarity with Microsoft Defender.” Thanks for the heads-up!
• SharePoint & Teams Leaks: Misconfigured public-facing SharePoint sites and Teams chats? Jackpot. I scrape these for internal documents, org charts, and even passwords carelessly shared in discussions.
• Dark Web Treasures: Data breaches from other companies might have left your credentials exposed. I buy them cheap, test them on your M365 tenant, and sometimes I strike gold.

How You Can Stop Me: ? Train employees on what not to share online. ? Regularly scan for publicly accessible SharePoint sites and Teams groups. ? Enforce strong password policies and MFA.

Phase 2: Entry – Walking Through the Front Door

Now that I know your weaknesses, it’s time to break in. The easiest ways?

1. Brute Force / Password Spraying – If your users use weak passwords and don’t have MFA enabled, I’m in within minutes.
2. OAuth Consent Phishing – Why steal credentials when I can just trick a user into giving me app permissions?
3. 3rd-Party Apps – Many organizations don’t monitor the permissions granted to external applications. If I can get a malicious app approved, I own your data.

How You Can Stop Me: ? Enforce MFA for every user—no exceptions. ? Monitor OAuth permissions and remove unused or excessive privileges. ? Use Conditional Access to block risky logins.

Phase 3: Privilege Elevation – Becoming an Admin in Your Own Tenant

Getting into your system is one thing. Taking control is another. Here’s how I escalate privileges:

• Finding Forgotten Global Admins – Many organizations have way too many admin accounts. I find the ones you forgot about.
• Exploiting Misconfigured Entra Apps – Some apps have insane permissions. If I can hijack one, I have the keys to the kingdom.
• PowerShell Execution – If I get access to a privileged account, I can automate the entire attack and blend in with normal admin activity.

How You Can Stop Me: ? Follow the principle of least privilege—limit Global Admins. ? Monitor and audit Entra ID application permissions. ? Restrict PowerShell access to only authorized users.

Phase 4: Persistence – Making Sure You Can’t Kick Me Out

Once I have control, I make sure you can’t get rid of me. I might:

• Create New Admin Accounts – Even if you kick out my entry point, I have backups.
• Modify Security Policies – If I change your conditional access rules, I can keep coming back.
• Set Up Auto-Forwarding on Emails – I can spy on your conversations indefinitely.

How You Can Stop Me: ? Audit all new admin account creations. ? Track changes to security policies in real time. ? Block external email forwarding unless explicitly approved.

Phase 5: Exfiltration & Ransom – The Endgame

By this point, I have options. I can:

• Steal and Sell Your Data – I dump everything valuable and sell it on the dark web.
• Deploy Ransomware – I encrypt your entire tenant and demand payment.
• Use Your Tenant for Future Attacks – I can use your M365 to launch phishing attacks on your partners.

How You Can Stop Me: ? Regularly back up and test disaster recovery plans. ? Implement User Behavior Analytics (UBA) to detect anomalies. ? Secure all endpoints and cloud access points.

Final Thoughts: Can You Stop Me?

Cybersecurity isn’t about if you’ll be attacked—it’s about when. The Microsoft 365 ecosystem is massive, complex, and filled with attack vectors. But here’s the good news: You have the power to fight back.

With CoreView’s security and governance solutions, you can:

• Gain complete visibility into your Microsoft 365 environment.
• Detect misconfigurations and security risks before they are exploited.
• Automate security policies to stay ahead of attackers.

Your move. Will you take control, or will I?

Let’s talk: How are you securing your M365 tenant? Drop a comment below!