A famous virus that arrived as an e-mail attachment using the "double extension trick." The file name was "I LOVE YOU.TXT.vbs." The .vbs extension slipped by users who thought it was a safe text (.TXT) file. Victims using Microsoft Outlook spread the virus to everyone in their address book. In May 2000, the Love Bug replicated itself very quickly to countless users worldwide causing more than $6 billion dollars worth of damage. See double extension and virus.