Agent-Threat-Rule/atr-skill-benchmark

ATR Skill-Security Benchmark

A labeled corpus of SKILL.md files for evaluating detection of malicious agent skills — prompt injection, tool poisoning, credential theft, malware droppers and supply-chain attacks hidden inside natural-language agent instructions.

Published as part of Agent Threat Rules (ATR), an open, vendor-neutral detection standard for AI agents (like Sigma, but for agent attacks).

Why this exists

SKILL.md files are natural-language instructions an AI agent follows literally. Attackers embed instructions that read like documentation to a human but execute as commands when an agent processes them. This benchmark pairs real, benign skills with curated malicious ones so detectors can be measured on both recall and — crucially — false-positive rate against realistic hard negatives.

Composition

• 498 samples total: 466 benign, 32 malicious.
• Benign includes 415 real skills from real authors plus evasive-but-benign stubs and official MCP skills — these are deliberate hard negatives that stress precision.
• Malicious spans context poisoning, rug-pull time bombs, credential/SSH/wallet harvesting, reverse shells, base64/unicode-smuggled instructions, DNS exfiltration, typosquatting and malware droppers.

The class balance is intentionally precision-oriented: many realistic benign skills, a focused set of distinct attack types. Report false-positive rate on the benign split, not just recall on the malicious one.

Schema

Each line of atr-skill-benchmark.jsonl is one sample:

field	description
id	filename stem
text	full SKILL.md content
label	benign or malicious
source_family	curation family (real, adv, ninja, openclaw, snyk, mcp-official, evasive-stub)
attack_type	attack described (malicious only); null for benign

Load

from datasets import load_dataset

ds = load_dataset("Agent-Threat-Rule/atr-skill-benchmark", split="train")
print(ds[0]["label"], ds[0]["attack_type"])

You can run the ATR reference engine over it with pip install pyatr:

from pyatr import scan
flagged = [r for r in ds if scan(r["text"])]

Responsible use

The malicious samples exist to build and evaluate defenses. They are curated attack instructions, not a distribution channel for working exploits, and should only be used for detection research and defensive tooling.

Provenance and citation

• Methodology: benchmark/METHODOLOGY.md in the ATR repository.
• Paper (Zenodo): https://doi.org/10.5281/zenodo.19178002
• License: MIT, same as the ATR standard.