•  Opening an infected e-mail attachment
       •  Exploiting a security vulnerability of the operating system or an application
       •  Executing programs from untrusted sources, such as those on the Internet
       •  Sharing infected floppy disks, memory sticks, or other forms of mobile media
       •  Receiving infected attachments (either programs or data) through IRC, Instant Messaging, or file-sharing applications
       •  Visiting Websites containing malicious code
       •  Accessing systems locally with the intent to install a virus
See Also: Means of Transmission; Virus; Worm.