Qiusi Zhan

I am a third-year Ph.D. student at the University of Illinois Urbana-Champaign (UIUC), advised by Prof. Daniel Kang. My research focuses on identifying and mitigating safety vulnerabilities in (multimodal) large language models (LLMs) and LLM-based agents for real-world deployment.

News

2026.01	One paper accepted to ICLR 2026.
2026.01	One paper accepted to EACL 2026 Findings.
2025.11	Will join Meta FAIR as a research intern in Summer 2026 (Menlo Park).

Selected Publications

Visual Backdoor Attacks on MLLM Embodied Decision Making via Contrastive Trigger Learning
Qiusi Zhan*, Hyeonjeong Ha*, Rui Yang, Sirui Xu, Hanyang Chen, Liang-Yan Gui, Yu-Xiong Wang, Huan Zhang, Heng Ji, Daniel Kang
ICLR, 2026
website / arXiv / code

SafeSearch: Do Not Trade Safety for Utility in LLM Search Agents
Qiusi Zhan, Angeline Budiman-Chan, Abdelrahman Zayed, Xingzhi Guo, Daniel Kang, Joo-Kyung Kim
EACL Findings, 2026
arXiv / code

Adaptive Attacks Break Defenses Against Indirect Prompt Injection Attacks on LLM Agents
Qiusi Zhan, Richard Fang, Henil Shalin Panchal, Daniel Kang
NAACL Findings, TrustNLP Workshop Spotlight, 2025
arXiv / code

InjecAgent: Benchmarking Indirect Prompt Injections in Tool-Integrated Large Language Model Agents
Qiusi Zhan, Zhixiang Liang, Zifan Ying, Daniel Kang
ACL Findings, 2024
arXiv / code

Removing RLHF Protections in GPT-4 via Fine-Tuning
Qiusi Zhan, Richard Fang, Rohan Bindu, Akul Gupta, Tatsunori Hashimoto, Daniel Kang
NAACL, 2024
arXiv

Academic Services

Reviewer for ARR, NeurIPS, and ICLR.
Recognized as “Top Reviewer” at NeurIPS 2025.

Experience

	University of Illinois Urbana-Champaign · 2023.08 – Present Ph.D. Student in CS · Advisor: Prof. Daniel Kang
	University of Illinois Urbana-Champaign · 2021.08 – 2022.12 M.S. in ECE · Advisor: Prof. Heng Ji
	Peking University · 2017.09 – 2021.07 B.S. in CS · Advisor: Prof. Sujian Li
	University of California Santa Barbara · 2020.07 – 2020.09 Visiting Research Student · Advisor: Prof. Xifeng Yan

Internship

	Amazon, WA · 2025.05 – 2025.08 Applied Scientist Intern · Mentor: Joo-Kyung Kim
	Microsoft, WA · 2024.05 – 2024.08 Data Scientist Intern · Mentor: Yu Hu
	JD.COM Silicon Valley Research Center, CA · 2022.01 – 2022.05 Research Scientist Intern · Mentor: Lingfei Wu
	ByteDance, Beijing · 2021.04 – 2021.07 Applied Scientist Intern · Mentor: Bo Zhao