History of Yahoo!
On March 8, 1997, Yahoo! acquired online communications company Four11. Four11's webmail service, Rocketmail, became Yahoo! Mail. Yahoo! also acquired ClassicGames.com and turned it into Yahoo! Games. Yahoo! then acquired direct marketing company Yoyodyne Entertainment, Inc. on October 12, 1998. In January 1999, Yahoo! acquired web hosting provider GeoCities. Another company Yahoo! took over was eGroups, which became Yahoo! Groups in June 2000. On March 8, 1998, Yahoo! launched Yahoo! Pager, an instant messaging service that was renamed Yahoo! Messenger a year later.
Yamanner
The Yamanner worm is a computer worm written in javascript that targeted a vulnerability in the Yahoo! Mail service. Released on June 12, 2006, the worm spread through the Yahoo! system, infecting the systems of those who opened the e-mails and sending the user's address book to a remote server.