Slopsquatting: LLMs hallucinate package names attackers pre-register (react-codeshift, unused-imports)

'Slopsquatting' is a supply-chain attack that weaponizes a systematic AI failure: coding agents confidently recommend packages that do not exist. Across 576,000 code samples generated by 16 different LLMs, roughly 19.7% of recommended packages were hallucinations — and when identical prompts were re-run ten times, 43% of the fake names appeared on every single run. That predictability is the exploit: an attacker runs a few dozen prompts, harvests the names that consistently recur, and registers them as malware before anyone else. Documented cases include react-codeshift (a name an LLM produced by conflating the real jscodeshift and react-codemod tools) and unused-imports (hallucinated in place of eslint-plugin-unused-imports). npm's typosquatting collision detection offers no defense, because hallucinated names are brand-new strings with nothing to collide against.