The worm spreads through email attachments and usenet.[19][20][21] When executed, animated fireworks and a "Happy New Year" message display.[19][22] The worm modifies Winsock, a Windows communication library, to allow itself to spread.[19] The worm then attaches itself automatically to all subsequent emails and newsgroup posts sent by a user.[23] The worm modifies a registry key to automatically start itself when the computer is rebooted.