This talk delves into the recent discovery of the XZ-Utils backdoor (CVE-2024-3094), a vulnerability that shook the open-source community. We'll explore how this hidden exploit compromised the integrity of a widely trusted compression tool. Attendees will gain insights into the broader implications for software security, best practices for detecting similar threats, and strategies to restore trust in compromised systems. Join us as we unpack the technical details, the aftermath, and the lessons learned from this significant breach.