Using OpenAI Codex to Automate Indirect Prompt Injection Attacks Against Claude Sonnet on Amazon Bedrock

This article details the author's process of using OpenAI's Codex to automate the generation, testing, and refinement of indirect prompt injection payloads targeting agentic AI systems running Claude Sonnet 4.5 and 4.6 models on Amazon Bedrock. The project started as an effort to