Senior/Staff Attack Engineer, Rapid Response

Summary

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.

You will focus on high-consequence vulnerabilities that are actively exploited, newly disclosed, or likely to generate significant attention - from CISA Known Exploited Vulnerabilities (KEVs) and Zero-Days to N-Days and emerging attack techniques. You will turn vulnerability research and attacker tradecraft into safe, repeatable, automated attack capabilities for the issues that are in the news, creating urgent customer concern, or most likely to affect the broader security community. This is not a traditional consulting or manual-pentesting role. Your work will help

security teams rapidly validate exposure, prioritize remediation, and verify that defenses are working.

What You’ll Do

• 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.

What You Bring

• 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.

Nice to Have

• 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.

Travel Required

We are a fully remote company, and this job may require up to 10% of travel to be successful.

Perks of Horizon3

• Inclusive Team: We value diversity and promote an inclusive culture where everyone can thrive.

• Base salary range: $230,000 - $275,000 annually. The exact salary will be determined based on the selected candidate’s location, qualifications, experience, and relevant skills.

You Belong Here

Horizon3 is not just an equal opportunity employer - we are a community that values diversity, equity, and inclusion as fundamental principles of our culture and success. We are dedicated to fostering a workplace where everyone feels welcome and respected, regardless of race, color, religion, sex, national origin, age, disability, veteran status, sexual orientation, gender identity or expression, genetic information, marital status, or any other legally protected status by law.