Episode sponsors: Binarly, the supply chain security experts (https://binarly.io) XZ.fail backdoor detector (https://xz.fail) Malware paleontologist Costin Raiu returns for an emergency episode on the XZ Utils software supply chain backdoor. We dig into the timeline of the attack, the characteristics of the backdoor, affected Linux distributions, and the reasons why 'Tia Jan' is the handiwork of a cunning nation-state. Based on all the clues available, Costin pinpoints three main suspects -- North Korea's Lazarus, China's APT41 or Russia's APT29 -- and warns that there are more of these backdoors lurking in modern software supply chains. Links: Binarly XZ backdoor detectorXZ Utils Backdoor FAQ (by Dan Goodin)CISA advisory on backdoorThe JiaT75 (Jia Tan) timelineUnedited transcript