The Windows XP MEMZ typically spread through infected executable files, which were often shared on peer-to-peer (P2P) networks and via email attachments. When an infected file was run on a Windows XP system, the malware would install itself and begin to execute its payload.
What made MEMZ legendary wasn't the damage it did to the Master Boot Record (MBR); it was the journey there. Once executed, it didn't hide. It announced itself with a parade of internet memes and system hijinks: windows xp memz