Spotting and Stopping the Evil Proxy Attack in Microsoft 365

Spotting and Stopping the Evil Proxy Attack in Microsoft 365

In the ever-evolving landscape of cyber threats, the Evil Proxy Attack stands out as a sophisticated method used by cybercriminals. MSPs (Managed Service Providers) must remain vigilant, especially when managing Microsoft 365 environments. In this article, we'll break down the components of this malicious strategy and how we're actively guarding against it.

Understanding the Evil Proxy Attack

At its core, the Evil Proxy Attack utilizes a Malicious Proxy to intercept communications between a client and a server. The attacker leverages this Man-in-the-Middle (MitM) Attack strategy to gain unauthorized access and manipulate data. For Microsoft 365 users, this typically unfolds in four critical stages:

1. Phishing Ambush: Users receive a seemingly innocent email, often masquerading as a trusted or even internal contact. However, these emails contain malevolent content, laying the groundwork for the attack.

2. MFA Misdirection: The attacker adds a new MFA (Multi-Factor Authentication) method to the victim's account, ensuring they can regain access even if initial entry points are closed.

3. Suspicious Sign-ins: The attacker logs into the victim's account, often from unexpected or high-risk locations.

4. Inbox Infiltration: To remain undetected, attackers modify inbox rules. Typically, they'll divert incoming messages to an 'archive' folder and mark them as read, ensuring the user remains oblivious to their actions.

Proactive Protections Against Proxy Threats

Fortunately, our suite of tools is equipped to detect and counter these attacks:

1. Email Shield: We employ advanced mechanisms that both warn and block emails that show signs of spoofing or contain suspicious links/attachments.

2. Inbox Alert: Any new inbox rules created on a user's account immediately trigger a notification to the admin, ensuring prompt action against any suspicious activity.

3. Location Guard: Our system notifies admins when an account logs in from outside specified safe regions. We also offer the option to block such suspicious logins outright.

What's Next?

By Quarter 4 of 2023, we're adding another layer to our security quilt. Soon, we'll notify you whenever a new MFA method is added to a user's account – a direct counter to one of the key steps in an Evil Proxy Attack.

Remember, the Proxy Server plays a crucial role in maintaining the flow of data between client and server. It's this very role that attackers exploit, sometimes even employing SSL/TLS interception tactics to decipher encrypted data. Being aware of the modus operandi of such attacks and having proactive measures in place is the key to keeping your Microsoft 365 environment secure.

In conclusion, by staying updated and vigilant, MSPs can effectively guard against the cunning and deceptive Evil Proxy Attack.