信息网络安全 ›› 2026, Vol. 26 ›› Issue (9): 1354-1368.doi: 10.3969/j.issn.1671-1122.2026.09.003

• 入选论文 • 上一篇    下一篇

大语言模型微调阶段的后门投毒:攻击、防御与评估

马文飞1,2, 龙春1,2(), 李婧1, 杨帆1, 付豫豪1   

  1. 1 中国科学院计算机网络信息中心, 北京 100083
    2 中国科学院大学计算机科学与技术学院, 北京 101408
  • 收稿日期:2026-06-06 出版日期:2026-09-10 发布日期:2026-09-30
  • 通讯作者: 龙春 E-mail:anquanip@cnic.cn
  • 作者简介:马文飞(2002—),男,河南,硕士研究生,主要研究方向为大模型安全和隐私计算|龙春(1979—),男,湖北,正高级工程师,博士,CCF会员,主要研究方向为攻击检测、恶意域名检测、网络流量分析|李婧(1983—),女,吉林,高级工程师,博士,主要研究方向为密码协议设计与分析|杨帆(1981—),女,北京,高级工程师,硕士,主要研究方向为网络空间安全、云安全|付豫豪(1988—),男,河南,高级工程师,硕士,主要研究方向为网络空间安全
  • 基金资助:
    国家重点研发计划(2023YFC3304704)

Backdoor poisoning in the fine-tuning stage of large language models: attacks, defenses, and evaluation

Ma Wenfei1,2, Long Chun1,2(), Li Jing1, Yang Fan1, Fu Yuhao1   

  1. 1 Computer Network Information Center, Chinese Academy of Sciences, Beijing 100083, China
    2 School of Computer Science and Technology, University of Chinese Academy of Sciences, Beijing 101408, China
  • Received:2026-06-06 Online:2026-09-10 Published:2026-09-30
  • Contact: Long Chun E-mail:anquanip@cnic.cn

摘要:

文章围绕大语言模型在指令微调、领域微调和参数高效微调阶段的后门投毒风险,采用文献综述、分类归纳与横向比较方法,系统梳理攻击、防御和评估研究。文章从投毒时机、触发模式与攻击目标归纳攻击方法,并按数据处理、训练约束、后门诊断和模型处置总结防御技术,同时统一攻击成功率、干净效用、错误触发率、隐蔽性及防御代价等指标。研究发现,现有工作主要关注训练前静态投毒和固定词法触发,语义、组合及多轮触发仍缺乏稳定定义和可靠检测方法,多数防御依赖特定触发假设、干净数据或模型访问权限,结论难以跨模型、跨任务迁移。研究认为,后续评估应明确威胁模型、数据来源、判定规则与访问条件,并加强持续微调和黑盒场景研究,以提升结果的可比性与可信度。

关键词: 大语言模型, 微调, 数据投毒, 后门攻击, 安全评估

Abstract:

Backdoor poisoning during large language model fine-tuning threatens model security, yet attacks, defenses, and evaluation practices remain fragmented. This review examined instruction tuning, domain adaptation, and parameter-efficient fine-tuning through a literature review, a taxonomic analysis, and a cross-study comparison. It classified attacks by poisoning timing, trigger pattern, and attack objective; It organized defenses into data processing, training-time constraints, backdoor diagnosis, and model remediation; And aligned key metrics such as attack success rate, clean utility, false trigger rate, stealthiness, and defense cost. The analysis showed that current studies focused mainly on static poisoning before training and fixed lexical triggers. Semantic, composite, and multi-turn triggers still lacked stable definitions and reliable detection methods. Most defenses depended on specific trigger assumptions, clean data, or model access, limiting transfer across models and tasks. The review concluded that comparable evaluation requires explicit threat models, data provenance, judging rules, and access conditions. Research on continual fine-tuning and black-box settings remains necessary to improve the comparability and credibility of security evaluations.

Key words: large language model, fine-tuning, data poisoning, backdoor attacks, security evaluation

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