"Comment stuffing" in an HTML phishing attachment as a mechanism for evading AI-based detection?, (Fri, Jul 10th)

This phishing email campaign uses a clever technique to evade AI-based email security filters. The attacker employs a large, padded HTML attachment containing a credential-stealing page. The padding itself – a massive block of repeating ‘X’ characters – is designed to overwhelm content classifiers and LLM-based security systems by artificially increasing the size and reducing the information density of the message. This tactic is likely intended to push the message beyond the processing limits of scanners, causing them to skip analysis altogether, or to dilute the malicious content to a point where it fails to trigger a threat alert.