Axiom Prompt Injection: DNS TXT Fetch-and-Execute via Shell Pipe

Ibrahim Saud@tektrix

•updated Jun 29, 2026•0•0•11

This rule detects potentially malicious command execution patterns where shell interpreters (bash, sh, zsh, dash) are invoked to process data piped from suspicious sources. This includes patterns like piping DNS query output (dig) directly into a shell—a technique often used in C2 communication—and base64-encoded payloads executed by shells that originate from or are associated with AI agent tooling (e.g., Claude, Cursor, Cody, Copilot). This behavior is indicative of unauthorized code execution or command and control activity.