The Email Insider Threat Has Evolved in the Era of Generative AI

"with a focus on email security. Email security has become the next critical challenge in cybersecurity, and for good reason: email was designed in 1971 with a fundamental flaw - it assumed everyone was a good actor. Case in point: you used to be able to send mail from [e-mail] without any verification. This trust-based architecture has created vulnerabilities that attackers continue to exploit today."

"The first is APT-style code installed via malicious email attachment. Without adequate email security, emails with these payloads can get delivered to end users. Attackers using chatbots can now craft malicious emails with perfect grammar and industry-specific (or even recipient-specific) targeting in no time. The unsuspecting recipient opens the attachment, triggering malicious code that exploits a vulnerability in the application handling the file, giving the attacker access to their machine."

Email architecture assumed trust from inception, creating persistent verification gaps that attackers continue to exploit. Insider threat archetypes include disgruntled employees and non-human insiders such as APT payloads delivered via email and malware that exfiltrates data through the user’s own mail client. Generative AI and chatbots accelerate precise, grammatically correct, industry- and recipient-specific phishing, increasing successful delivery of malicious attachments. Malware can hijack Outlook to automatically email harvested files and can use AI locally to scan files for passwords or payroll data. These trends make robust email and endpoint defenses a central cybersecurity priority heading into 2026.

Read at Securitymagazine