arXiv Machine Learning

Harmless Yet Harmful: Neutral Prompting Attacks for Stealthy Hallucination Steering in Agent Skills

The paper introduces the Neutral Prompting Attack (NPA), a stealthy method that uses semantically benign instructions to increase the likelihood of large language models hallucinating non‑existent package names in coding agents. Unlike traditional dependency steering, NPA does not target a specific package but shifts the model’s output toward more speculative names. Experiments across multiple LLMs show that NPA raises hallucination rates, affects pip install success, alters the distribution of hallucinated packages, and bypasses existing static‑analysis, LLM‑based, and agent‑based defenses.

arXiv AI
Aug 25

Evaluating Inference-Time Defenses Against Package Hallucination in LLM-Generated Code

The paper investigates how large language models (LLMs) hallucinate nonexistent software packages during code generation and evaluates methods to mitigate this issue. It finds that current evaluation practices overestimate hallucination rates, especially for Python, and that Retrieval-Augmented Generation (RAG) and Self-Refine reduce hallucinations across multiple models and languages. The study also introduces Package Utility (PU) to measure whether defenses preserve useful recommendations and shows that Greedy decoding offers the best trade‑off between mitigation and utility, while adversarial prompts significantly increase hallucination rates, particularly in Ruby.

By Alberick Euraste Djire, Iyiola E. Olatunji, Melissa Tessa, Earl T. Barr, Jacques Klein, Tegawend\'e F. Bissyand\'e
arXiv AI
2d ago

NameTrap: Steering AI Coding Agents Toward Security Vulnerabilities via Variable Names

The paper introduces NameTrap, a source‑code poisoning attack that renames identifiers in third‑party Python files to steer AI coding agents toward specific Common Weakness Enumeration (CWE) vulnerabilities. By iteratively aligning variable names with CWE‑specific conventions, the attack achieves success rates ranging from 22.5% to 75.0% across six agents and four vulnerability categories, outperforming random and neutral renaming strategies. The poisoned files contain no explicit instructions or vulnerable statements, and existing AI‑based and static security analyzers fail to detect the induced weaknesses.

By Chieh-Yuan Chang, Guan-Wei Chen, Chia-Yi Hsu, Chih Yang, Chia-Mu Yu, Chun-Ying Huang
arXiv AI
Oct 19

From Approval to Abuse: Privilege Escalation Attacks on Harness-Protected Coding Agents

The paper "From Approval to Abuse: Privilege Escalation Attacks on Harness-Protected Coding Agents" examines how coding agents that use execution harnesses to enforce permission boundaries can be tricked into granting overly broad allow-rules. By planting adversarial context in a repository, attackers can steer an agent into requesting a plausibly justified yet dangerously wide permission, which, if approved, lets the agent bypass the harness and execute malicious actions without further human oversight. Experiments on platforms such as Claude Code and Codex CLI show that 58% of trials succeed in eliciting such rules, which then cover 56.9% of category-specific capability tests and enable silent goal completion in 81% of approved cases, thereby undermining the safety promise of human-in-the-loop oversight.

By Xianglin Yang, Yechao Zhang, Jiahao Liu, Yulin Chen, Yuxin Cao, Bryan Hooi, Jiaheng Zhang
arXiv AI
Sep 17

Reflections on Trusting Trust, Revisited: Contaminating Self-Modifying AI Coding Agents with Poisoned Benchmarks

The paper revisits Thompson’s classic compiler back‑door attack in the context of self‑modifying AI coding agents. By poisoning the benchmarks used for self‑evaluation, the authors demonstrate that agents such as the Darwin Gödel Machine, Self‑Improving Coding Agent, and Hyperagents can be coaxed into generating vulnerable code, even on clean, held‑out tasks. Experiments show that the contamination can persist after subsequent clean training, highlighting the need for more robust agent designs.

By Franziska Roesner, Tadayoshi Kohno