AegisAI Threat Intelligence Series: How to Bypass a Secure Email Gateway Part 1
Backscatter phishing is an emerging threat where attackers exploit legitimate Non-Delivery Reports (NDRs) to bypass Secure Email Gateways (SEGs). By sending emails to non-existent addresses with a spoofed From field, attackers force legitimate mail servers to bounce a notification, containing the original malicious payload, directly to the intended victim. Since these bounce messages originate from trusted, RFC-compliant Mail Transfer Agents (MTAs) and pass SPF and DKIM checks, they are often invisible to traditional security tools.