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// articles by tag "spam"

Articles by tag "spam"

Case

Zero-Width Space Characters: A Unicode Attack on Spam Filters

Zero-width space (ZWSP) and other invisible Unicode characters are used by spammers to bypass keyword-based spam filters. This article explains how the attack works, which characters are commonly abused, and how to defend your spam filtering pipeline against them.

Mar 20, 2026 • 6 min read