"Comment stuffing" in an HTML phishing attachment as a mechanism for evading AI-based detection?, (Fri, Jul 10th)
2026-07-10T13:23:47Z•3b91df81aa248fb4be96a085c16b20b8e79b11c83b8812cfab6269be387f56de
ai-evasionattachment-sandboxingcomment-stuffingdetection-evasionemail-attachmentevasionhtml-commentmail-filteringphishingsans_isc
What happened
SANS ISC highlights a phishing sample that uses “comment stuffing” inside HTML attachments to evade AI- and heuristic-based detectors. Attackers inject large amounts of HTML comments and benign-looking noise to alter tokenization/feature extraction, obscure malicious text and links, and frustrate simple parsers and ML models. Impact is increased likelihood of content-based detection bypass and false negatives for mail filters and attachment scanners. Recommended mitigations include normalizing/stripping HTML comments before analysis, rendering and analyzing the DOM (not just raw source), doing
Why it matters
A reviewed impact interpretation has not been published for this record.
Evidence and limitations
- Source ID
- sans_isc_diary
- Record identifier
- 3b91df81aa248fb4be96a085c16b20b8e79b11c83b8812cfab6269be387f56de
- Enrichment time
- 2026-07-10T13:23:47Z
- AI-assisted enrichment
- Yes
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