Senior External Attack Engineer: Autonomous Pentests

Get to Know Us

Horizon3 is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find, fix and verify exploitable attack vectors before criminals exploit them. Our flagship product, the NodeZeroTM platform, delivers production-safe autonomous pentests and other key assessment operations that scale across the largest internal, external, cloud, and hybrid cloud environments. Node Zero has been adopted by organizations of all sizes, from small educational institutions to government agencies and Global 100 enterprises.

It is used by IT Ops/Sec Ops teams, consulting pentesters, and MSSPs and MSPs.

We are a fusion of former U.S. Special Operations cyber operators, startup engineers & operators, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools and false positives, resulting in alert fatigue, blind spots, "checkbox” security culture, cybersecurity skills shortage, and the long lead time and expense of hiring outside consultants. Collectively, we are a team of learn it alls, committed to a culture of respect, collaboration, ownership, and results.

An Overview

We're looking for a Senior Attack Engineer to drive key work streams within our external attack capabilities in Node Zero, our autonomous pentesting platform.

For most organizations, the external attack surface is where a breach begins. Customers need Node Zero to find the forgotten host, exposed credential, or misconfigured service, and prove how far each weakness leads. The surface is large and messy. It spans domains, certificates, cloud assets, code repositories, leaked data, identities, SaaS tenants, and the relationships connecting all of it. Much of it is unstructured, inconsistent, and hard to reason about in code.

Attackers are also getting faster at finding and chaining these weaknesses together.

This is a high-impact role. You'll independently develop complex work streams within our external attack domain: contributing to the research and content roadmap, building deep expertise the team relies on, and helping raise the bar for the engineers building alongside you.

This is not consulting or manual pentesting. The goal is to turn the manual recon and multi-step attack work that skilled operators do by hand into safe, reliable, repeatable workflows that run autonomously against some of the largest external attack surfaces in the world.

What You’ll Do

• Design, build, and maintain highly scalable reconnaissance workflows that discover, enumerate, and fingerprint external-facing assets and services in production-grade Python.

• Research, explore, and parse large volumes of external-facing data, including unstructured and inconsistent sources, and turn it into accurate, actionable information.

• Develop robust approaches to data that is hard to reason about in code, such as free-form banners, web content, documents, and error output, and build parsing and enrichment that holds up across the long tail of real environments.

• Collect, store, and connect high volumes of information, and extend our attack-path modeling and graph data model to represent new identity, privilege, and relationship paths.

• Traverse identity relationships across the external surface, such as accounts, tenants, SSO and federation, exposed credentials, and third-party services, to find paths from exposure to compromise.

• Automate multi-step attack workflows that chain discovery, credential access, initial access, and post-exploitation into complete, safely proven attack paths.

• Research emerging external tradecraft and turn it into production attack content, with an emphasis on techniques that still succeed against hardened, well-monitored targets.

• Stand up and maintain representative test environments to validate, demonstrate, and regression-test attack scenarios.

• Build for production safety and scale: respect target and customer environments, rate limits, and scope while running across very large attack surfaces.

• Contribute to priorities and the coverage roadmap based on real customer environments, threat intelligence, and emerging techniques.

• Mentor teammates and proactively support their growth, and help define team standards for code quality, research rigor, and operational safety.

• Collaborate cross-functionally with engineers, product managers, and customer-facing teams, and author internal documentation and external research and blog posts.

What You’ll Bring

• Deep,…