Spoof is nothing but a recycled ZBot, more specifically Trojanjan.Spy.Zbot.UI, detected as Trojan.ZBot.UI. ZBot is known to transform the infected machines into spaming relays, sending hundreds of messages without the users knowledge or consent, consuming valuable network and computing resources. The message is: Michael Jackson dead? NO!!! The message was sent to a target website, advertising sexual enhancement drugs and spreading malware. The email that sent the message to the target looked like this: “The file presented as the file with secret information”]
Source: https://www.bitdefender.com/blog/hotforsecurity/michael-jacksons-unknown-killer/