Step into the shoes of an enigmatic cybersecurity expert who uncovers a catastrophic event in the open-source world: an insidious backdoor in XZ Utils that threatens to compromise millions of systems. As you delve deeper, you'll navigate through a web of deception, collaboration, and espionage. Utilizing your skills in profiling, reverse engineering, and social engineering, you'll have to piece together clues from a myriad of sources while making critical decisions that will determine the fate of open-source security. Can you outsmart the villainous threat actor before it's too late?