---
title: "🚨 Day One Defence: Stopping a Microsoft 365 Breach in Real Time"
description: A new client’s Microsoft 365 account was targeted on day one — our MDR and 24/7 SOC stopped the breach before any damage was done.
image: https://blog.paac-it.com/hubfs/security%20alert%20banner.png
---

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# 🚨 Day One Defence: Stopping a Microsoft 365 Breach in Real Time

![Richard Paterson](https://blog.paac-it.com/hs-fs/hubfs/rich%202.0.png?width=120&height=120&name=rich%202.0.png)

 by [Richard Paterson](https://blog.paac-it.com/blog/author/richard-paterson)

Jul 25, 2025, 9:57:23 AM

There’s nothing quite like starting with a win.

This week, one of our newest clients had only just been onboarded when our 24/7 Security Operations Centre received a high-risk sign-in alert — late in the evening. The alert was triggered by **Microsoft Entra ID**, which we deploy as standard for all clients, and was backed up by our **Managed Detection and Response (MDR)** integration with Microsoft 365.

### What Happened

- Multiple suspicious sign-in attempts were detected from global locations
- The attacker was using a VPN to try and hide their tracks
- They were using a **real, compromised password** that had been in use for months

Within minutes:

- All sign-in sessions were revoked
- The account was secured and the password was reset
- A full investigation was launched

The client was informed, the risk was stopped, and no data was accessed.

### The Source? Password Reuse

The attacker had gotten hold of the password through an unrelated third-party breach — and had been quietly trying to brute-force their way in ever since. The client wasn’t aware, because they had no visibility. Now they do.

### Why It Matters

This is exactly why we include **Entra ID**, **MDR**, and **24/7 SOC coverage** as part of our default protection stack:

- 🔍 Alerts surface in real time
- ⛔ Dangerous sessions are stopped automatically
- 🧠 Investigations are fast and informed
- 🛡️ Clients are protected before they even realise there’s a threat

### The Takeaway

Our client avoided a full account compromise because the right tools were in place from day one.

Now the only job left? Updating every other service where that same password was used — a good reminder that **password reuse is still one of the biggest risks to your business**.

---

**Want to know if your Microsoft 365 account would alert on a breach?**  
We’ll run a no-obligation review and show you what’s missing.

![lighthouse](https://139498162.fs1.hubspotusercontent-eu1.net/hub/139498162/hubfs/lighthouse.png?width=1200&length=1200&name=lighthouse.png)

![eset protect](https://139498162.fs1.hubspotusercontent-eu1.net/hub/139498162/hubfs/eset%20protect.png?width=1200&length=1200&name=eset%20protect.png)

**Tags:**

![Richard Paterson](https://blog.paac-it.com/hs-fs/hubfs/rich%202.0.png?width=120&height=120&name=rich%202.0.png)

Post by [Richard Paterson](https://blog.paac-it.com/blog/author/richard-paterson)  
 Jul 25, 2025, 9:57:23 AM

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