Your code review passed. Your SAST scan passed. The commit history is clean. And your production binary is backdoored.
This talk examines what happens when an attacker targets the build environment rather than the source code. CI/CD runners, the agents that compile code, run tests, and produce artifacts represent one of the most powerful and least scrutinized positions in the modern software supply chain. Control the runner, and you control what gets shipped, without touching a single line in the repository.
We walk through how a runner-level compromise works in practice: how trust boundaries in build pipelines are structured, where they break down, and how an attacker can inject malicious changes into a final build artifact while leaving the source code, commit history, and security scans completely untouched. As AI-assisted code review becomes standard practice, this blind spot grows more dangerous because the build environment sits entirely outside what those tools can see.
The talk closes with a live demonstration of a CI/CD pipeline compromise on a realistic target workflow, showing the full arc from initial access to a poisoned artifact and what it would take to actually catch it.

What the Audience Will Walk Away With:

- A clear mental model of where trust boundaries exist in CI/CD pipelines and exactly where they can be broken
- An understanding of how runner-level compromise enables supply chain attacks that bypass source code review, SAST, and AI-assisted PR analysis
- A live demonstration showing a realistic pipeline compromise producing a backdoored artifact from a clean repository
- Concrete defensive measures — including artifact signing with Sigstore/Cosign, SLSA build provenance, and ephemeral runner strategies — that directly address the attack surface covered in the talk