About the Job
Horizon3 is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find and fix and verify exploitable attack vectors before criminals exploit them. Our flagship product, the NodeZeroTM platform, delivers production-safe autonomous pentests and other key assess...
We are a fusion of former U.S. Special Operations cyber operators, startup engineers, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools, false positives resulting in alert fatigue, blind spots, "checkbox” security culture, c...
We are hiring a Staff Attack Engineer to join the team behind our Rapid Response product. You will research and productize real-world exploitation techniques so customers can quickly understand whether newly disclosed or actively exploited vulnerabilities affect their environments—and what an attacker could do next.
Key Responsibilities
Research and reproduce high-consequence vulnerabilities across enterprise networks, applications, identity systems, cloud environments, and infrastructure—including CISA KEVs, CVEs, N-Days, and Zero-Days.
Study attacker tactics, techniques, procedures, and campaigns observed in the wild, including tradecraft not tied to a single CVE.
Turn vulnerability research and real-world attacker behavior into safe, repeatable proof-of-exploit capabilities, attack paths, and automated modules for Rapid Response and NodeZero.
Demonstrate realistic impact—including privilege escalation, credential access, lateral movement, persistence, and data access—without unnecessary disruption.
Validate remediation and containment by safely retesting vulnerabilities and security controls.
Improve execution speed, reliability, observability, and evidence quality while collaborating with research, product, and engineering teams.
Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee. Duties, responsibilities, and activities may change at any time with or without notice.
In any materials you submit, you may redact or remove age-identifying information such as age, date of birth, or dates of school attendance or graduation. You will not be penalized for redacting or removing this information.
Required Skills & Abilities
Strong Python and software engineering skills, including experience building, testing, and operating production-quality tooling.
Solid penetration testing, vulnerability research, and exploit-development fundamentals.
Hands-on experience with enterprise networks, applications, identity systems, cloud environments, or endpoint security.
Demonstrated ability to reproduce vulnerabilities and convert manual techniques into reliable automation.
Understanding of common attack chains, trust boundaries, authentication and authorization, privilege escalation, and lateral movement.
Ability to balance speed, safety, reliability, coverage, and actionable evidence.
Curiosity about how attackers exploit newly disclosed vulnerabilities and how defenders can validate exposure quickly.
Strong ownership, judgment, and communication skills in ambiguous or time-sensitive situations.
Experience with CISA KEVs, CVE analysis, N-Day research, Zero-Day research, or responsible disclosure.
Background in incident response, threat hunting, purple teaming, or security operations.
Experience with AWS, Azure, GCP, Kubernetes, Active Directory, Entra ID, Okta, or hybrid environments.
Experience with exploit development, reverse engineering, malware analysis, or vulnerability research.
Contributions to security research, CVEs, conference talks, open-source tools, or technical publications.
CTF experience or equivalent hands-on offensive security practice.
Bachelor’s Degree in Computer Science, Computer Engineering or related field.
OSCP (Offensive Security Certified Professional) or equivalent certifications.
