Attackers are leveraging a novel technique called phantom squatting, which exploits domain hallucinations generated by large language models (LLMs) to target software supply chains. This method enables adversaries to create fake web domains that appear legitimate, increasing the likelihood of successful supply chain attacks. By manipulating LLMs into generating these "hallucinated" domains, attackers can bypass traditional security controls and infiltrate the supply chain. The phantom squatting technique poses a significant threat to organizations relying on LLMs for domain validation, as it can lead to unauthorized access and malicious activity. Researchers at Palo Alto Unit42 have identified this emerging threat vector, highlighting the need for enhanced security measures to mitigate the risk of phantom squatting1. This development matters to security practitioners because staying ahead of such innovative attack techniques is crucial for protecting software supply chains from increasingly sophisticated threats.