In May 2017, the world witnessed a massive ransomware outbreak known as WannaCry, orchestrated by the notorious Lazarus APT group. Exploiting the EternalBlue vulnerability in Microsoft SMB protocol, the ransomware spread rapidly, causing widespread panic and disruption. As a senior cyber threat intelligence analyst, your mission is to dissect this attack, understanding its propagation mechanics, identifying potential kill-switch domains, and determining if decryption is possible without succumbing to ransom demands.