6. Melissa Virus – $1.2 Billion
It is named after a stripper in Miami and distributed by David L. Smith from New Jersey; he served 20 months in prison and was fined $5000. Melissa typically spread through List.doc or other infected files; and sends itself to 50 first email addresses from the address book. It commonly affects Microsoft Word 97 and 2000, as well as Excel 97, 2000 and 2003.