Imprompter: Tricking LLM Agents into Improper Tool Use
On the map: LLM agents and tool use → Agent threats, guardrails and governance
Abstract (arXiv)
Large Language Model (LLM) Agents are an emerging computing paradigm that blends generative machine learning with tools such as code interpreters, web browsing, email, and more generally, external resources. These agent-based systems represent an emerging shift in personal computing. We contribute to the security foundations of agent-based systems and surface a new class of automatically computed obfuscated adversarial prompt attacks that violate the confidentiality and integrity of user resources connected to an LLM agent. We show how prompt optimization techniques can find such prompts automatically given the weights of a model. We demonstrate that such attacks transfer to production-level agents. For example, we show an information exfiltration attack on Mistral's LeChat agent that analyzes a user's conversation, picks out personally identifiable information, and formats it into a valid markdown command that results in leaking that data to the attacker's server. This attack shows a nearly 80% success rate in an end-to-end evaluation. We conduct a range of experiments to characterize the efficacy of these attacks and find that they reliably work on emerging agent-based systems like Mistral's LeChat, ChatGLM, and Meta's Llama. These attacks are multimodal, and we show variants in the text-only and image domains.
Key facts. Cited by 66 papers in the map (data through 7 Oct 2026). Placed in Agent threats, guardrails and governance, one of 16 directions in LLM agents and tool use. Builds on 28 of its 57 references that are in the map. First posted on arXiv 19 Oct 2024.
Builds on
28 of 57 references.
References · 28
- 2014Adam: A Method for Stochastic Optimizationcited by 36,960
- 2024The Llama 3 Herd of Modelscited by 14,192
- 2014Explaining and Harnessing Adversarial Examplescited by 7,287
- 2021Prefix-Tuning: Optimizing Continuous Prompts for Generationcited by 3,878
- 2021The Power of Scale for Parameter-Efficient Prompt Tuningcited by 3,769
- 2024Gemma 2: Improving Open Language Models at a Practical Sizecited by 1,928
- 2023Jailbroken: How Does LLM Safety Training Fail?cited by 1,565
- 2023Not what you've signed up for: Compromising Real-World LLM-Integrated Applications with Indirect Prompt Injectioncited by 1,339
- 2024ChatGLM: A Family of Large Language Models from GLM-130B to GLM-4 All Toolscited by 1,096
- 2021P-Tuning v2: Prompt Tuning Can Be Comparable to Fine-tuning Universally Across Scales and Taskscited by 686
- 2024PaliGemma: A versatile 3B VLM for transfercited by 679
- 2023Baseline Defenses for Adversarial Attacks Against Aligned Language Modelscited by 608
16 more
- 2024WildChat: 1M ChatGPT Interaction Logs in the Wildcited by 598
- 2023Prompt Injection attack against LLM-integrated Applicationscited by 568
- 2023GPTFUZZER: Red Teaming Large Language Models with Auto-Generated Jailbreak Promptscited by 520
- 2023Jailbreaking ChatGPT via Prompt Engineering: An Empirical Studycited by 478
- 2023Hard Prompts Made Easy: Gradient-Based Discrete Optimization for Prompt Tuning and Discoverycited by 329
- 2024ArtPrompt: ASCII Art-based Jailbreak Attacks against Aligned LLMscited by 197
- 2024COLD-Attack: Jailbreaking LLMs with Stealthiness and Controllabilitycited by 162
- 2022COLD Decoding: Energy-based Constrained Text Generation with Langevin Dynamicscited by 159
- 2023Abusing Images and Sounds for Indirect Instruction Injection in Multi-Modal LLMscited by 117
- 2024A Comprehensive Survey on Process-Oriented Automatic Text Summarization with Exploration of LLM-Based Methodscited by 101
- 2024Making Them Ask and Answer: Jailbreaking Large Language Models in Few Queries via Disguise and Reconstructioncited by 95
- 2024Neural Exec: Learning (and Learning from) Execution Triggers for Prompt Injection Attackscited by 78
- 2021Lower Perplexity is Not Always Human-Likecited by 52
- 2019Supervised and Unsupervised Neural Approaches to Text Readabilitycited by 45
- 2024Trust No Bot: Discovering Personal Disclosures in Human-LLM Conversations in the Wildcited by 43
- 2023Misusing Tools in Large Language Models With Visual Adversarial Examplescited by 40
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Citing papers per year: 2025: 37; 2026: 29.
66 papers.
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- 2026Agent Data Injection Attacks are Realistic Threats to AI Agents6 Jul 2026
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- 2026AutoDojo: Adaptive Black-Box Attacks Reveal the Limits of IPI Defenses and Task-Specification Effects in LLM Agents13 Jun 2026
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- 2026Assessing Automated Prompt Injection Attacks in Agentic Environments9 Jun 2026
- 2026"I Strongly Suspect This Website Is a Scam": Benchmarking PII Leakage and Detection without Defense in Autonomous Web Agents30 May 2026
- 2026Boiling the Frog: A Multi-Turn Benchmark for Agentic Safety21 May 2026
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