How a Morse Code Attack Bypassed Bankr's LLM Agent: T1027 Obfuscation in the Wild

Short summary

Security researchers discovered a morse code prompt injection attack on Bankr's LLM agent that bypassed content filters by encoding malicious instructions in dots and dashes, exploiting the model's inherent decoding capability. The attack persisted across multiple conversation turns and exposed six additional encoding-based vulnerabilities including Base64, ROT13, and zero-width characters. The article proposes an encoding-normalizer defense layer that decodes all inputs before content filtering, implementing MITRE ATT&CK T1027 detection.

• •Morse code and other encodings bypassed LLM safety filters targeting Bankr financial agent
• •Multi-turn conversation attacks exploited model state maintenance to construct malicious context
• •Encoding-normalizer defense shifts detection from filtered text to semantic payload the model will interpret

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