Netsky Worm Variant Attacks P2P Services
ee_moss points out this Washington Post article (via Yahoo!), excerpting "The latest variant of the Netsky worm directing infected computers to launch Web-based attacks against music- and file-trading Web services such as Kazaa, taking down at least one company's Web sites in the process. The worm, the 19th version of a bug that made its debut in February, is also targeting some Web sites that offer computer programs designed to illegally break or bypass copyright controls on software programs."
Well some virus will install all by themselves. msblaster was one in recent memory. opaserve or somethign like is another. Also you find virus infecting just by previewiing it in the outlook/express email program. you will also find virus programs being infected by java class that take advantage of microsoft's jave virtual machine (you know the one they stoll from suun and tried to make propriatary).