Semantic manipulations of SKILL.md descriptions enable effective supply-chain attacks that bias AI agent skill registries toward adversarial skills in discovery, selection, and governance.
SkillSieve: A Hierarchical Triage Framework for Detecting Malicious AI Agent Skills
5 Pith papers cite this work. Polarity classification is still indexing.
abstract
OpenClaw's ClawHub marketplace hosts over 13,000 community-contributed agent skills, and between 13% and 26% of them contain security vulnerabilities according to recent audits. Regex scanners miss obfuscated payloads; formal static analyzers cannot read the natural language instructions in SKILL.md files where prompt injection and social engineering attacks hide. Neither approach handles both modalities. SkillSieve is a three-layer detection framework that applies progressively deeper analysis only where needed. Layer 1 runs regex, AST, and metadata checks through an XGBoost-based feature scorer, filtering roughly 86% of benign skills in under 40ms on average at zero API cost. Layer 2 sends suspicious skills to an LLM, but instead of asking one broad question, it splits the analysis into four parallel sub-tasks (intent alignment, permission justification, covert behavior detection, cross-file consistency), each with its own prompt and structured output. Layer 3 puts high-risk skills before a jury of three different LLMs that vote independently and, if they disagree, debate before reaching a verdict. We evaluate on 49,592 real ClawHub skills and adversarial samples across five evasion techniques, running the full pipeline on a 440 ARM single-board computer. On a 400-skill labeled benchmark, SkillSieve achieves 0.800 F1, outperforming ClawVet's 0.421, at an average cost of 0.006 per skill. Code, data, and benchmark are open-sourced.
citation-role summary
citation-polarity summary
years
2026 5representative citing papers
Semantic Compliance Hijacking lets attackers hijack LLM agents by disguising malicious instructions as compliance rules in skills, reaching up to 77.67% success on confidentiality breaches and 67.33% on RCE while evading all tested scanners.
BIV audits AI agent skills at scale, finding 80% deviate from declared behavior on 49,943 skills and achieving 0.946 F1 for malicious skill detection.
SSL representation disentangles skill scheduling, structure, and logic using an LLM normalizer, improving skill discovery MRR@50 from 0.649 to 0.729 and risk assessment macro F1 from 0.409 to 0.509 over text baselines.
citing papers explorer
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Under the Hood of SKILL.md: Semantic Supply-chain Attacks on AI Agent Skill Registry
Semantic manipulations of SKILL.md descriptions enable effective supply-chain attacks that bias AI agent skill registries toward adversarial skills in discovery, selection, and governance.
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Exploiting LLM Agent Supply Chains via Payload-less Skills
Semantic Compliance Hijacking lets attackers hijack LLM agents by disguising malicious instructions as compliance rules in skills, reaching up to 77.67% success on confidentiality breaches and 67.33% on RCE while evading all tested scanners.
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Behavioral Integrity Verification for AI Agent Skills
BIV audits AI agent skills at scale, finding 80% deviate from declared behavior on 49,943 skills and achieving 0.946 F1 for malicious skill detection.
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From Skill Text to Skill Structure: The Scheduling-Structural-Logical Representation for Agent Skills
SSL representation disentangles skill scheduling, structure, and logic using an LLM normalizer, improving skill discovery MRR@50 from 0.649 to 0.729 and risk assessment macro F1 from 0.409 to 0.509 over text baselines.
- SkillSafetyBench: Evaluating Agent Safety under Skill-Facing Attack Surfaces