The Code Red worm was a computer worm first observed on July 13, 2001 that attacked computers running Microsoft's IIS web server. It caused widespread infections, reaching over 359,000 infected hosts by July 19th. The worm spread via email messages with the subject line "I Love You" and defaced infected websites with the message "Hacked By Chinese!". While initially a failure, attacks on online payment systems like E-gold in 2001 were early experiments towards more sophisticated cyberattacks.