Email Security Bypass: Risks, Common Vectors, and How to Defend

Email security bypass occurs when attackers evade protections like spam filters, DMARC, DKIM, or gateway scanning to deliver malicious messages. Threat actors use tactics such as spoofed display names, compromised legitimate accounts, business email compromise (BEC), and cleverly obfuscated payloads to slip past defenses. Successful bypasses enable phishing, fraud, and malware delivery with higher trust and impact. To reduce risk, organizations should enforce strong email authentication (SPF/DKIM/DMARC), enable advanced threat detection (URL and attachment sandboxing), apply multi-factor authentication, and monitor account behavior for anomalies. Regular user training and simulated phishing tests further harden defenses against evasive email attacks.

Microsoft 365 Direct Send vulnerability

Microsoft 365’s Direct Send Feature Under Attack: How Cybercriminals Are Bypassing Email Security

Ravi Jain
exposes a significant vulnerability within Microsoft 365's Direct Send feature, explaining how it allows cybercriminals to bypass email security by impersonating internal users. This sophisticated phishing campaign leverages the feature's lack of authentication, enabling attackers to send malicious emails that appear to originate from within an organization, even without compromising any accounts. The article details the technical aspects of the exploit, including the use of PowerShell commands and specific indicators of compromise. Finally, it outlines critical mitigation strategies for organizations, emphasizing enhanced monitoring and advanced email security solutions to combat this difficult-to-detect threat. ... Read More