Teach LLMs to Phish: Stealing Private Information from Language Models

ICLR 2025 Conference Submission296 Authors

Keywords: LLMs, machine learning, memorization, privacy, data poisoning, federated learning, large language models, privacy risks

Abstract:

When large language models are trained on private data, it can be a \textit{significant} privacy risk for them to memorize and regurgitate sensitive information. In this work, we propose a new \emph{practical} data extraction attack that we call ``neural phishing''. This attack enables an adversary to target and extract sensitive or personally identifiable information (PII), e.g., credit card numbers, from a model trained on user data with upwards of $10\%$ attack success rates, at times, as high as $50\%$.
Our attack assumes only that an adversary can insert as few as $10$s of benign-appearing sentences into the training dataset using only vague priors on the structure of the user data.

Submission Number: 296