Moderate-fitting as a Natural Backdoor Defender for Pre-trained Language Models - Zhu, Biru; Qin, Yujia; Cui, Ganqu; Chen, Yangyi; Zhao, Weilin; Fu, Chong; Deng, Yangdong; Liu, Zhiyuan; Wang, Jingang; Wu, Wei; Sun, Maosong; Gu, Ming (Advances in Neural Information Processing Systems, 2022)