1) Email worm 
Mydoom, also known as W32.MyDoom@mm, Novarg, Mimail.R and Shimgapi is a computer worm affecting Microsoft Windows. It was first sighted on January 26, 2004. It became the fastest-spreading e-mail worm ever ({as of|2004|1|lc=on}), exceeding previous records set by the Sobig worm and ILOVEYOU. Mydoom appears to have been commissioned by e-mail spamm...