# StepTrigger: Contact-State-Triggered Backdoor Attacks on VLM-Powered Legged Robots

- Source: arXiv cs.RO
- Published: 2026-10-27T04:00:00.000Z
- RoboHot: https://robohot.news/en/items/jxchw2529j2tjguw1n6vptcbv
- Original: https://arxiv.org/abs/2609.26131

## Summary

StepTrigger is a contact-state-triggered backdoor attack on VLM-powered legged robots. The trigger signal comes from the foot-ground contact pressure patterns produced when a Unitree Go1 quadruped walks across dense terrain, rather than from prompts or visible markers.