Virus creators often exploit known flaws in operating system software. Microsoft Windows, the operating system used on most computers, is a favorite target of virus creators. To thwart these individuals, Microsoft makes available software updates or patches to fix such flaws. These updates are available from Microsoft for free via the Internet. Windows can even be configured to automatically notify the user or automatically download and install these updates or both. In many cases, regularly installing these updates will immunize your computer from new and disruptive viruses.

E-mail has become a source of unwanted mail (commonly called “spam”). Such e-mail is clearly an annoyance. However, it can also provide a gateway for viruses to infect a computer or a computer network. Traditionally, most such viruses were contained in e-mail attachments. Enterprising virus creators have expanded their attacks so that viruses can be obtained even from e-mail without attachments. Nevertheless, a few simple actions can greatly minimize the likelihood of viruses affecting a computer. First, most antivirus programs can be set up to scan e-mail for viruses. Second, e-mail systems can be configured to reject all email attachments. Although blocking all attachments is very effective, it may compromise usability of e-mail such that it is counterproductive. A middle ground is to only block certain types of e-mail attachments such as types most likely to contain viruses. These are generally not the types of files routinely sent as file attachments, so in most cases this only has a minimal effect on system usability. Finally, file attachments, which are unexpected or from unknown users, should never be opened.

In addition to viruses, both legitimate enterprises and malevolent individuals have created and disseminated programs that illicitly collect and transmit data from a computer. Typically, these programs, called “spyware,” are unintentionally downloaded to a computer from the Internet. Often they are included, without any notice or warning, in things that are downloaded from the Internet. For example, downloading a free software program from the Internet may result in unwanted software being downloaded without your knowledge. Such software, known as a “Trojan Horse,” may come from a commercial enterprise which collects data on the web sites you visit on the computer, or it may be a program that collects critical data, such as usernames and passwords for later use in illegally penetrating the computer from a remote location. [See “Ethical Risks From the Use of Technology” by Andrew Beckerman-Rodau]