  As the pre-trained language models (PLMs) continue to grow, so do the
hardware and data requirements for fine-tuning PLMs. Therefore, the researchers
have come up with a lighter method called \textit{Prompt Learning}. However,
during the investigations, we observe that the prompt learning methods are
vulnerable and can easily be attacked by some illegally constructed prompts,
resulting in classification errors, and serious security problems for PLMs.
Most of the current research ignores the security issue of prompt-based
methods. Therefore, in this paper, we propose a malicious prompt template
construction method (\textbf{PromptAttack}) to probe the security performance
of PLMs. Several unfriendly template construction approaches are investigated
to guide the model to misclassify the task. Extensive experiments on three
datasets and three PLMs prove the effectiveness of our proposed approach
PromptAttack. We also conduct experiments to verify that our method is
applicable in few-shot scenarios.
