Piggi is a worm that spreads by e-mail through messages with infected attachments that can be executables, images, web pages, text documents or media files. Once the user opens such an attachment, the parasite secretly installs itself to the system and runs a spreading routine. It sends bogus e-mails to all the addresses it finds in the Windows Address Book and some local files. Piggi also creates hundreds of copies of itself in shared folders of popular peer-to-peer programs. This allows it to propagate through file sharing networks. Furthermore, it can infect remote computers by exploiting known security vulnerabilities. Piggi also carries a payload. It disables Windows and Symantec security software updates. The worm uses an integrated rootkit to hide its presence in the system. It is able to bypass the Windows Firewall. The parasite secretly runs on every Windows startup.