Security Engineering

Custom tooling, remediation, and DevOps security

Work with us

Overview

Our customer work and low-level research constantly surface the same foundational gaps: missing capabilities, brittle infrastructure, and vulnerabilities no off-the-shelf tool will catch. Security Engineering is the team that closes them, building custom tooling you can trust and remediating issues across development, testing, and continuous deployment.

You get engineers who have broken these systems before, not a staffing agency.

Why work with Trail of Bits

01

We broke these systems first

Our security engineers come from the offensive-research side of the practice. They've found the bugs they're now defending against, so the controls, tooling, and infrastructure they build are designed against real adversary behavior, not a checklist.
02

We publish everything

Custom tooling, hardening patterns, and infrastructure recipes end up in public open-source repos and the Trail of Bits blog. iVerify, osquery contributions, Buttercup, and our DARPA AIxCC work are all open, so what we build for you can build on the same foundations.
03

Deliverables your team can run with

Custom tools ship with documentation, training, and the rationale behind every design decision. Our goal is for your team to maintain and extend what we've built without needing us; if a solution requires Trail of Bits to stick around forever, it's not a good solution.

Services & deliverables

Custom Software Development

Service

Your organization has decided to add new software to its portfolio, either for customers or for internal operations. However, you don't have the time or dedicated resources, and you want certainty your final product is built on best practices in secure coding, has been thoroughly tested for vulnerabilities, and is hardened against known exploits.

Trail of Bits is your secure development partner. We have helped some of the world's leading security software companies bring reliable products to market. We will review existing software architectures and provide recommendations or fixes, enhance feature sets or write new capabilities, and improve your security testing via Trail of Bits proprietary or custom-built tools.

01: Research prototypes
02: Architecture design and review
03: Trusted component design
04: Secure development in C++, Python, Rust, and other languages
05: Secure development of embedded/IoT device firmware

Open Source Ecosystem Security

Service

Open Source has eaten the software world, and security is no exception. We believe in improving the security of existing open source ecosystems and in developing new security tooling for emerging ecosystems.

Security and quality engineering standards are essential to the longevity of the Open Source ecosystem. The best security tools are the ones that improve developers' lives, rather than adding friction or complexity to their workflows.

01: Package management and supply chain security, including dependency auditing and build security;
02: Code signing and high-integrity deployment;
03: Static and dynamic analysis tool development and integration;
04: High-velocity open-source security and cryptography engineering in the C++, Go, Rust, and Python ecosystems;

Case studies

Scalable security: We develop security features like API tokens and Two-Factor Authentication for PyPI, allowing hundreds of thousands of maintainers to improve the security of hundreds of millions of daily Python package installations.
Best practices: We build tools for mitigation detection in Windows binaries, helping our clients build CI/CD systems that prevent insecure binaries from being deployed to millions of end users.
Fatigue-free tooling: We build developer-friendly tools for dependency auditing and code signing, with an eye for open source and industry adopted standards.

Security Vulnerability Remediation

Service

It's not enough to test your software once. New releases are part of all software lifecycles, and new exploits are published every day.

If we find a security vulnerability, we'll work with you to fix it fast, then provide the information and know-how for you to achieve a hardened security posture.

01: Post-security-assessment bug fixes
02: Redesigning and refactoring code for security

Proactive Security: Measuring, Mitigating, and Enhancing

Service

Our engineers are bullish about improving security so incidents don't occur. From hardening software before it's deployed to adding security to your continuous integration (CI) process, our work mitigates the probability of show-stopping bugs impacting your company's mission.

01: Opting into available OS-level and compiler-level protections
02: Integrating libFuzzer fuzzing test cases into your codebase
03: Security Architecture and Design Reviews and risk assessment
04: Secure API design and implementation
05: Third-party software risk mitigation

DevOps/Operational Security

Service

Application development has become an integral part of business operations, and DevOps teams are highly incentivized to deliver new applications fast. Security can't be left out of the equation. Yet, many companies struggle to integrate security into DevOps workflows, even if it results in more secure software.

Rather than struggle to find the best processes, let Trail of Bits' engineers work with your DevOps team to implement:

We're experts in working alongside DevOps so we understand their processes and procedures, and our custom tools are built for seamless integration. Alleviate your interdepartmental struggles by allowing us to smooth the process while safeguarding against vulnerabilities.

01: Effective key management
02: Correctly configured roles
03: Proper infrastructure controls

What ships with every engagement

Most security-engineering shops hand you a binary and an invoice. Every Trail of Bits engagement ships a deliverable set your engineering team can own and extend after we leave.

Deliverable	Trail of Bits	Typical security-engineering shop
Source code + design docs Full source under permissive licensing where applicable, plus architecture decisions and rationale.	✓	Sometimes
Threat model on record Documented adversary, assumptions, and acceptance criteria, written before any code.	✓	—
Peer-reviewed by a second engineer Standard Trail of Bits practice; not a one-engineer project.	✓	—
Validation harness (fuzzing / SAST / dynamic) Tests our work continues to hold up after handoff.	✓	—
Training + knowledge transfer Live walkthroughs and documentation aimed at making your team self-sufficient.	✓	Sometimes
CI/CD integration ready Tools ship with the integration patterns your DevOps team needs to deploy them.	✓	—
Open publication of generalizable lessons Reusable patterns turn into public research so the whole industry benefits.	✓	—

Comparison based on the standard published deliverables of security-engineering and custom-tooling vendors, as of 2026.

How We Work

How we work

Whether we are building a tool, fixing a vulnerability, or hardening infrastructure, every Security Engineering engagement follows the same core approach. We start from the problem and the environment, design before we build, and build with an adversarial mindset. Then we validate that it holds up under attack and hand off the knowledge, not just the binary.

Understand the problem and environment.

We start by learning your systems, constraints, and threat model. Security engineering that ignores context produces solutions that don't fit. If you don't have a documented threat model, we help you build one.
Identify root causes, not just symptoms.

Before we write any code or configuration, we dig into why the problem exists. A vulnerability might indicate a missing pattern across your codebase. A DevOps gap might reflect unclear ownership. Solving the surface issue without addressing the underlying cause means you'll see the same problem again.
Design before building.

We document our approach, architecture decisions, and acceptance criteria before implementation begins. You review and approve the plan. No surprises.
Build with an adversarial mindset.

Our engineers have spent years finding vulnerabilities in systems like yours. When we write code or configure infrastructure, we assume someone hostile will eventually examine every line. Peer review by a second Trail of Bits engineer is standard.
Validate that it works.

We test our work through fuzzing, static analysis, manual review, or retesting, depending on the engagement. Security controls that look good on paper but fail in practice aren't security controls.
Hand off knowledge, not just deliverables.

You receive documentation, training, and the rationale behind our decisions. Our goal is for your team to maintain and extend what we've built without needing us. If a solution requires Trail of Bits to stick around forever, it's not a good solution.

Get in touch

Book a technical office hours session

Spend a free hour with one of our engineers on a specific technical problem: an architecture you're unsure about, a tool you want to stand up, a finding you can't reproduce. No pitch and no sales engineer, just a working session with someone who does this every day.

Book a session

We broke these systems first

We publish everything

Deliverables your team can run with

How we work

Understand the problem and environment.

Identify root causes, not just symptoms.

Design before building.

Build with an adversarial mindset.

Validate that it works.

Hand off knowledge, not just deliverables.

Book a technical office hours session