attack 2025

ArtPerception: ASCII Art-based Jailbreak on LLMs with Recognition Pre-test

Guan-Yan Yang 1,2, Tzu-Yu Cheng 1, Ya-Wen Teng 1,2, Farn Wanga 1, Kuo-Hui Yeh 3,4

2 citations · 71 references · Journal of Network and Compute...

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Published on arXiv

2510.10281

Prompt Injection

OWASP LLM Top 10 — LLM01

Key Finding

One-shot ASCII art jailbreak successfully bypasses safety alignment on GPT-4o, Claude Sonnet 3.7, and DeepSeek-V3, evading LLaMA Guard and Azure content filters with a reconnaissance-guided methodology

ArtPerception

Novel technique introduced


The integration of Large Language Models (LLMs) into computer applications has introduced transformative capabilities but also significant security challenges. Existing safety alignments, which primarily focus on semantic interpretation, leave LLMs vulnerable to attacks that use non-standard data representations. This paper introduces ArtPerception, a novel black-box jailbreak framework that strategically leverages ASCII art to bypass the security measures of state-of-the-art (SOTA) LLMs. Unlike prior methods that rely on iterative, brute-force attacks, ArtPerception introduces a systematic, two-phase methodology. Phase 1 conducts a one-time, model-specific pre-test to empirically determine the optimal parameters for ASCII art recognition. Phase 2 leverages these insights to launch a highly efficient, one-shot malicious jailbreak attack. We propose a Modified Levenshtein Distance (MLD) metric for a more nuanced evaluation of an LLM's recognition capability. Through comprehensive experiments on four SOTA open-source LLMs, we demonstrate superior jailbreak performance. We further validate our framework's real-world relevance by showing its successful transferability to leading commercial models, including GPT-4o, Claude Sonnet 3.7, and DeepSeek-V3, and by conducting a rigorous effectiveness analysis against potential defenses such as LLaMA Guard and Azure's content filters. Our findings underscore that true LLM security requires defending against a multi-modal space of interpretations, even within text-only inputs, and highlight the effectiveness of strategic, reconnaissance-based attacks. Content Warning: This paper includes potentially harmful and offensive model outputs.


Key Contributions

  • ArtPerception: a two-phase jailbreak framework using ASCII art to bypass LLM safety alignment — Phase 1 conducts a model-specific pre-test to find optimal ASCII art recognition parameters, Phase 2 launches a one-shot jailbreak attack
  • Modified Levenshtein Distance (MLD) metric for quantitatively evaluating LLM ASCII art recognition capability
  • Demonstrated transferability to commercial LLMs (GPT-4o, Claude Sonnet 3.7, DeepSeek-V3) and evasion of defenses including LLaMA Guard and Azure content filters

🛡️ Threat Analysis


Details

Domains
nlp
Model Types
llm
Threat Tags
black_boxinference_timetargeted
Applications
llm chatbotsgeneral-purpose language modelscontent moderation systems