This session introduces red teaming strategies for Agent-to-Agent (A2A) multi-agent systems, a new protocol for secure agent collaboration. We dissect the A2A lifecycle—capability discovery, task delegation, collaboration, and completion—and reveal how each phase presents unique security threats. Attendees will learn how to identify vulnerabilities, simulate attacks such as AgentCard poisoning, task lifecycle manipulation, and adversarial MIME payloads, and evaluate system resilience using a structured threat model. This session is ideal for researchers and practitioners building or defending agent-based AI systems.