Staff Attack Engineer, AI/LLM

Horizon3.ai is a fast-growing, remote cybersecurity company focused on helping organizations proactively identify and mitigate exploitable attack vectors. They are seeking a Staff Attack Engineer specializing in AI/LLM security to develop automated attacks for their NodeZero platform, aimed at enhancing offensive capabilities and ensuring the security of AI systems.

Responsibilities:

• Break AI and agentic systems and translate that research into automated, repeatable attack modules for NodeZero
• Design and execute prompt injection and defense evasion attacks, focusing on generalized, reusable patterns
• Conduct tool-use exploitation, abusing LLM agents’ access to code, file systems, APIs, and databases for attacker-realistic outcomes (e.g., context poisoning, RCE, data exfiltration, privilege escalation)
• Target AI infrastructure (model serving, training pipelines, vector databases, GPU/MLOps tooling) with an understanding of real-world enterprise deployments and misconfigurations
• Research and apply model and supply chain attacks (poisoning, training data extraction, adversarial inputs, deployment pipeline abuse)
• Perform threat modeling for agentic systems, mapping trust boundaries and attack surfaces and turning them into concrete attack paths
• Apply a strong productization mindset, turning manual techniques into safe, reliable, and scalable automated tooling
• Build and extend LLM-powered applications (prompting, structured output, agentic workflows)
• Design with production concerns in mind: cost, safety and hallucination guardrails, reliability, and observability
• Design and extend microservices that orchestrate LLM tasks and integrate with NodeZero and related offensive workflows

Requirements:

• Expert-level Python and software engineering skills
• Solid penetration testing fundamentals and understanding of common attack chains
• Familiarity with AI/LLM security frameworks (e.g., OWASP Top 10 for LLMs, MITRE ATLAS)
• Experience in a security product or offensive security team, ideally with shipped offensive capabilities or tooling
• Proven ability to break AI/LLM and agentic systems
• Clear understanding of trust boundaries around AI tools, data sources, and permissions, and how to systematically test and exploit them
• Expert-level ownership – drives high-complexity, high-risk programs and sets strategy, not just execution
• Self-motivated – identifies problems and builds solutions proactively
• Industry obsessed – tracks the fast-moving AI security landscape and can speak to recent developments, new attacks, and where the field is heading
• Experience with other cloud AI services (e.g., Azure OpenAI, GCP Vertex AI)
• Contributions to AI security research (blog posts, conference talks, CVEs, open-source tools)
• Experience with AWS Bedrock and AWS Agent Core
• Familiarity with graph databases (e.g., Neo4j)
• Background in traditional exploit development or vulnerability research
• CTF experience, particularly in AI/ML-focused challenge categories