Email Security The Rising Threat of Phishing and the Role of Microsoft 365
Phishing attacks are becoming increasingly sophisticated, targeting businesses of all sizes. IT administrators and security professionals must ensure robust email security; it's not just a best practice, it's a necessity. This guide explores how to maximize your Microsoft Defender for Office 365 (M365) anti-phishing settings.
This article focuses on maximizing M365 anti-phishing settings including configuration and common challenges. We'll dive into impersonation protection, mailbox intelligence, safety tips, and more to help fortify your defenses.
Impersonation Strengthening Your Defenses: Leveraging Protection
Impersonation attacks, where attackers masquerade as trusted individuals or brands, are a significant source of phishing incidents. M365's impersonation protection allows you to watch for and quarantine emails mimicking high-profile colleagues or your organization's domains.
Recommended configuration involves identifying protected users (e.g., executives) and adding them manually, ensuring domain protection includes all your organization's domains, and opting for the Quarantine action for impersonated senders.
Mailbox Intelligence Unveiling the Power of
Mailbox intelligence analyzes historical email patterns to create a "contact graph" for each user, recognizing unusual senders or activity. This works seamlessly with impersonation protection to catch fraud and spear-phishing.
Depending on your team's capacity to address quarantined emails, enable Mailbox Intelligence and Mailbox Intelligence Protection in groups. Flagged emails will be automatically quarantined for review.
User Education Empowering Users with Safety Tips
Microsoft's safety tips visually alert users to potentially harmful emails, which can be configured to display during various scenarios like first contact alerts, domain/user impersonation tips, and odd character detection.
These educational cues make users a key part of your anti-phishing strategy and are some of the easiest settings to implement.
“Security isn’t just about tools—it’s about getting them right.
Chris Singlemann
Enhance Your Security Posture
Explore these interactive elements for deeper understanding:
Phishing Risk Assessment
Test your knowledge with a short quiz and identify potential vulnerabilities in your current setup.
M365 Settings Checklist
Download a checklist to ensure you've covered all critical anti-phishing settings.
Authentication Understanding Spoof Intelligence and Indicators
Spoof Intelligence detects spoofing beyond standard email protocols. Features like Unauthenticated Sender Indicators and "Via" Tagging add clarity to email authenticity.
It's essential to honor external senders' DMARC policies with your settings, setting "Quarantine" or "Reject" actions for emails failing DMARC to prevent exposure to harmful content.
Troubleshooting Addressing Common Issues with M365 Anti-Phishing Settings
Configuration drift can occur; regular monitoring is crucial. Conflict can occur if multiple anti-phishing policies are assigned to the same group. Monitor policies and how they apply to high-risk user groups, consider reviewing phish threshold sensitivity and whitelisted domains.
If malicious domains are frequently getting through, disabling end-user controls is often a consideration. Review third-party email gateway settings and ensure proper configuration to avoid compromising built-in protections.
Taking Action Making the Most of Your M365 Security Tools
With Microsoft 365’s anti-phishing tools, you don’t have to choose between convenience and comprehensive protection. Configure policies, leverage mailbox intelligence, and enable user-facing safety features to create a multi-layered defense.
Optimize your configurations with a 14-day free trial of Prelude to understand your current M365 policy configuration and identify areas for improvement. Take your setup further, and ensure your configurations are optimized.