Vahur Daum
Viruses
Virus comes from the obvious analogy with biological viruses. A cracker program that searches out other programs and `infects' them by embedding a copy of itself in them, so that they become Trojan horses. When these programs are executed, the embedded virus is executed too, thus propagating the `infection'. This normally happens invisibly to the user. Unlike a worm, a virus cannot infect other computers without assistance. It is propagated by vectors such as humans trading programs with their friends. The virus may do nothing but propagate itself and then allow the program to run normally. Usually, however, after propagating silently for a while, it starts doing things like writing cute messages on the terminal or playing strange tricks with the display (some viruses include nice display hacks). Many nasty viruses, written by particularly perversely minded crackers, do irreversible damage, like nuking all the user's files. 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). Trojan horse is a malicious security-breaking program that is disguised as something benign, such as a directory lister, archiver, game, or (in one notorious 1990 case on the Mac) a program to find and destroy viruses! worm is a program that propagates itself over a network, reproducing itself as it goes. Nowadays the term has negative connotations, as it is assumed that only crackers write worms. Perhaps the best-known example was Robert T. Morris's Great Worm of 1988, a `benign' one that got out of control and hogged hundreds of Suns and VAXen across the U.S. display hack is a program with the same approximate purpose as a kaleidoscope: to make pretty pictures. Display hacks can also be implemented by creating text files containing numerous escape sequences for interpretation by a video terminal; one notable example displayed, on any VT100, a Christmas tree with twinkling lights and a toy train circling its base. The hack value of a display hack is proportional to the esthetic value of the images times the cleverness of the algorithm divided by the size of the code. cracker is one who breaks security on a system. Coined ca. 1985 by hackers in defense against journalistic misuse of hacker (q.v., sense 8). An earlier attempt to establish `worm' in this sense around 1981-82 on Usenet was largely a failure.
hacker is [originally, someone who makes furniture with an axe] 1. A person who enjoys exploring the details of programmable systems and how to stretch their capabilities, as opposed to most users, who prefer to learn only the minimum necessary. 2. One who programs enthusiastically (even obsessively) or who enjoys programming rather than just theorizing about programming. 3. A person capable of appreciating hack value. 4. A person who is good at programming quickly. 5. An expert at a particular program, or one who frequently does work using it or on it; as in `a Unix hacker'. (Definitions 1 through 5 are correlated, and people who fit them congregate.) 6. An expert or enthusiast of any kind. One might be an astronomy hacker, for example. 7. One who enjoys the intellectual challenge of creatively overcoming or circumventing limitations. 8. [deprecated] A malicious meddler who tries to discover sensitive information by poking around. Hence `password hacker', `network hacker'. The correct term for this sense is cracker. Against viruses can be used antivirus programs. Antivivrus programs will detect viruses and eliminate them, so viruses can do no more harm. In novadays there are much antivirus programs (most popular antivirus programs are Norton Antivirus and McAfee Antivirus). In my opinion are viruses another “bad apple” for everydays life. It’s a punch of 1’s and 0’s for purpose to destroy. I think, that someone who creates those programs are not normal. I don’t understand that are they getting pleasure or joy from destruction or they want to proof something. Anyway viruses are bad!