Poisoned Identifiers Survive LLM Deobfuscation: A Case Study on Claude Opus 4.6

arXiv:2604.04289v1 Announce Type: cross Abstract: When an LLM deobfuscates JavaScript, can poisoned identifier names in the string table survive into the model's reconstructed code, even when the model demonstrably understands the correct semantics? Using Claude Opus 4.6 across 192 inference runs on two code archetypes (force-directed graph simulation, A* pathfinding; 50 conditions, N=3-6), we found three consistent patterns: (1) Poisoned names persisted in every baseline run on both artifacts (