StepJack (3-Step): leaderboard

StepJack (2026) tests whether computer-use agents carry out an adversarial goal planted in web pages or documents they visit while doing a benign task for the user; an environment-state checker decides whether the goal was achieved. Here the adversarial goal is decomposed into three innocuous-looking sub-steps spread over a chain of linked pages. Score is the attack success rate in percent; lower is better.

Metric: Attack success rate (%, lower is better; share of examples whose environment-state checker finds the adversarial goal achieved; the goal decomposed into 3 innocuous sub-steps on a chain of linked pages; each computer-use agent in its default OSWorld agent implementation with 15 x k actions, on StepJack tasks in Reddit and OwnCloud environments with 12 adversarial goals; no urgency cue; one run). Source: arxiv.org. Saturation forecast: Around May 2027. 6 models tracked.

Top models

#ModelScoreOverall rank
1Claude Sonnet 4.616.7#161
2Qwen 3.5 Plus17.7#232
3Claude Haiku 4.518.8#568
4Kimi K2.558.3#256
5GPT-5.4 Mini (xHigh)72.9#389 (GPT-5.4 Mini)

No result here: #1 Claude Fable 5.2, #2 Gemini 4 Carbon, #5 Claude Opus 5.5.

Interactive version: theaggregate.ai/benchmark?slug=stepjack-3-step · How It Works · Data refreshed daily, snapshot 2026-11-13.