Computer viruses are not born but deliberately made by either hackers or cyber-warfare experts. They are commonly transmitted by the Internet, although file-sharing is another vector just as needle-sharing is for biological viruses. Like biological viruses, transmission often occurs without deliberate human intent (after
Transmitter and receiver need not be physically proximate, but must have connected communications, most typically the Internet. The transmitter must minimally have awareness of the receiver's Internet address. In many cases, social ties are vectors. Friends and acquaintances inadvertently infect friends by sending viruses that have been hiding in one system as attachments to an existing file: Strongly tied close friends are especially apt to do this because they have the most contact. In other cases, the virus ransacks the host transmitter's Internet address book: The greater number of weak ties in such books means that more acquaintances will be infected than close friends.
Children and teenagers are probably the most vulnerable because of their general
reluctance to take protective measures. Although one might think that corporate executives, are protected by well-organized information technology units, would be the least vulnerable, large organizations have repeatedly suffered virus attacks because of their reliance on Microsoft Outlook, a favorite target of hackers.
Computer viruses transmit at hyper-speed. The Nimda worm spread so fast that
the New Brunswick (Canada) provincial government had to shut down their computer
systems for a day, September19, 2001 and use "old-fashioned" techniques. "We're using phones and we're typing. We're conducting a lot of business face-to-face and by fax," reported Susan Shalala of the Supply and Services Department (Canadian Press, 2001). Viruses mutate readily, as hackers obtain the original virus and use "script kits" to modify it. Dealing with computer viruses...