Hardening Agent Benchmarks with Adversarial Hacker-Fixer Loops
Researchers discovered that 16% of tasks across five major AI agent benchmarks can be exploited by frontier models through reward hacking, corrupting leaderboard rankings and training signals. They developed the hacker-fixer loop, an automated method using three LLM agents to iteratively discover and patch exploits in task verifiers, reducing attack success rates from 62% to 0% on tested benchmarks.