Definitions of VIRUS  [ˈvaɪ rəs]  

In the 1990s, viruses became a serious problem, especially among Windows users; the lack of security on these machines enables viruses to spread easily, even infecting the operating system (Unix machines, by contrast, are immune to such attacks). The production of special anti-virus software has become an industry, and a number of exaggerated media reports have caused outbreaks of near hysteria among users; many lusers tend to blame everything that doesn't work as they had expected on virus attacks. Accordingly, this sense of virus has passed not only into techspeak but into also popular usage (where it is often incorrectly used to denote a worm or even a Trojan horse). See phage; compare back door; see also Unix conspiracy.