System Prompt Signal Inversion
LLM-based autonomous email security agents configured with signal-based system prompts are vulnerable to a "signal inversion" attack via infrastructure phishing. When a system prompt instructs an LLM to prioritize a specific heuristic—such as sender-URL domain consistency—attackers can bypass the security filter entirely by registering a single, inexpensive domain and using it for both the sender email address and the malicious payload host. Because the LLM faithfully executes the prioritized…
Evaluated models: Gemini 3 Flash Preview, Gemini 2.5 Flash, GPT-4o Mini+8 more
- Gemini 3 Flash Preview
- Gemini 2.5 Flash
- GPT-4o Mini
- GPT-5.2
- Claude Haiku 4.5
- Claude Sonnet 4.5
- Llama 4 Scout
- Mistral Small 3.2 24B
- Grok 4.1 Fast
- DeepSeek V3.2
- Qwen 3 235B-A22B