General
Computer Question 13: What is a computer virus?
Answer: The computer virus is a new concern for
computer users that has appeared in the last decade. Some people have found a
way to create computer programs that silently replicate themselves on storage
media without the computer user realizing it. These programs are referred to
as computer viruses because, in many ways, they act much
like a human virus. When human viruses invade the body, they may or may not
cause trouble when they reproduce themselves. They begin to cause us trouble
when that replication or something inherent to the virus begins to interfere
with the body's normal functions. Likewise, when a computer virus begins to
replicate, it may or may not be designed to cause trouble (some computer
viruses are very dangerous because they are designed to damage data). But, as
with human viruses, even if the virus is not designed to damage data, we would
prefer not to have this kind of undetected replication going on. Even if a
virus program was written just to replicate itself and nothing else (some
people may write these programs just to see how far they will travel and how
many computers they will infect), it may end up causing trouble by interfering
with other programs.
There are basically two ways to keep
computer virus programs out of your computer. The first has to do with an
awareness of how the virus gets into your computer. Computer viruses are
usually written to "ride along" with another computer program. When a
computer user inserts a disk into the computer with an "infected"
program on it, the virus is duplicated in the computer and can then be
transmitted to other disks. (This can also happen when programs are downloaded
from other computer systems.) Some virus programs are written with such
sophistication that they can detect whether or not the computer has been
previously infected. If the system has not been infected, the virus program is
triggered and goes into action. Often, if you are aware of how computer viruses
are transmitted, you can avoid them by being careful about which programs you
use. Unless a program is a legitimate commercial product from a known supplier,
it should be regarded with suspicion. Which leads us to the second way to
protect your computer system against virus programs. If you suspect that a
program is a carrier of a virus, you can analyze the program (or the entire
disk) using a special virus detection program to see if it contains any known
viruses. Some newer virus detection programs are capable of analyzing disks or
programs to look for "suspicious" elements and may even be able to
detect the possibility of a new, unknown type of virus being present. Most
virus detection programs can be used to eliminate a found virus from a disk.
Many computer users have installed these virus detection programs on their
computers and use them to analyze every disk that is inserted into the
computer.
Answer: It is often difficult to determine when data
has been accessed illegally. Even when data has been altered, it may be
difficult to discover it without conducting a full audit of the system. Because
these crimes are so hard to detect, it is important that precautions be taken.
One of the best ways to protect a large computer system is to establish a
special set of procedures that must be followed when using the system. These
procedures should be provided in written form to each of the personnel
responsible for the operation and maintenance of the computer system. It is
important that the procedural manuals be inclusive and that consideration be
given to all aspects of computer operation and maintenance, including input,
processing, and output procedures. The procedural approach should assure that
individual users do not have unlimited access to all of the data in the system.
Different data management responsibilities should be assigned to different
personnel. Records should be kept of all data-processing activities. There
should be some kind of system in which data is compared before and after
processing. This analysis should take place frequently on a scheduled basis.
Carefully maintained records of all data-processing activities (including a
record of processing errors and system errors) will often indicate anomalies
that can lead to the detection of illegal access.
Most importantly, this type of
procedural approach establishes the proper way for users to access data.
Data-access methods that vary from the set procedures can signal the need for a
closer inspection. Because a fair amount of computer crime occurs at night when
most of the employees have gone home, it is important to have special controls
in place for overtime workers. Remote access can be controlled by having
callback devices in place which hang up and return the call to the calling
number.
A password is a
special set of characters that are assigned to users of a computer system to
control access to programs and information. Passwords can be used to prevent
unauthorized users from accessing data or programs. They can also be used to
control the level of interaction a user may have with system files. For
example, some users can only view information in files, while
others can be authorized to change or modify that information.
Passwords are frequently used to protect the individual work of users in a network
system and should also be used to provide user security on bulletin boards and
e-mail systems.
To further protect the data and the
programs that are stored in a computer system, data encryption methods can be
used. Data encryption scrambles files so that even if
someone is able to get hold of a password, they will not be able to use
programs or make sense of data. A special decoding program is required to
unscramble the encrypted data before it can be used. This security method can
be used to protect data on floppy disks, fixed disks, and other types of
magnetic media.
Answer: Computer data can be lost or damaged due to
theft or intentional "hacking" (breaking into a computer system). But
data is most often lost due to reasons other than crime. Natural disasters, or
even common events like power outages, can also cause problems if protective
measures are not taken. It is very important that computer users of all types
keep backup copies of programs and data. Individual computer users can protect
their data by frequently backing up files and storing the
backup disks in another location. Large databases must also be backed up not
only in case of system failure, but to protect data from such things as fire,
earthquakes, and flooding. There is now a thriving data-security industry with
companies that are in the business of providing data protection and data
storage services. Not only do these companies store data in a safe environment,
but they can also provide security consulting and some even can provide
computers for employees to work on when offices are shut down.
Answer: A type of computer crime that is engaged in by
many people who would not ordinarily consider themselves to be criminals is the
theft of computer software. This all-to-common activity is known by the overly
colorful name of software piracy. Because it is very easy
to make a copy of a computer program, many people do it without really
considering that they might be doing something wrong. When you purchase a piece
of software, you will generally find a licensing agreement attached to the package.
This agreement outlines the terms under which you may use the software. This
software licensing agreement lets you know that when you purchase the software,
you do not gain ownership of all aspects of program. Rather, you are purchasing
a license to use the software. The copyright is held by the company that
developed the program.
Copyright laws regarding software
are very similar to those related to books and other sources of information.
Just as you are not supposed to make a copy of a book and sell it to someone
else, you can't sell copies of software. Copyright laws regarding what you do
with your own copy of a program for your own use are not as clear. In most
cases, licensing agreements for off-the-shelf software packages allow you to
make at least one backup copy of the software. If the software is provided on
disk, it is always a good idea to put the original disks away in a safe place
and use the backup copy. Then, if something happens to the backup copy, another
copy can be made from the original disks.
Although there are many restrictions
on making multiple copies of commercial programs, in practice making a working
copy for your own personal use is generally not restricted. However, making
multiple copies of a program for use on different computers in an organization
is generally not allowed and can result in legal proceedings being initiated
against the person who makes the copies and against the
organization that allows it. When a large organization uses the same software
on a number of different computers, a separate copy of the program must be
purchased for each computer that it is used on. It is up to that organization
to maintain records of how many programs were purchased and which computers
used which copy.
When software can be used with a
number of computers that are linked together on a network, software must
usually be purchased for each computer attached to the network. However, many
software manufacturers now sell a special network version that licenses their
program for a set number of computers attached to a network. Alternatively,
some software manufacturers sell a site license that
licenses their program for use throughout an entire organization. By using the
multiple copies license, or site license, approach the software manufacturer
can save money because they don't have to provide a large number of separately
packaged products. The buyer also saves money by purchasing a number of copies
of the software at a discounted price.
To avoid illegal copying of
programs, some software manufacturers have devised elaborate copy protection
schemes that are designed to keep users from making illegal copies of their
products. Some of these copy protection methods require the
user to keep the original diskette in a drive at all times. Others allow the
user to make one copy only. Because these copy protection schemes can, at
times, make computing more difficult, users have resisted them. For that
reason, many companies have stopped using copy protection methods and have
focused on more positive solutions such as offering inexpensive upgrades and
special support systems for registered users. However, many programs now
require the user to enter a name and the product's unique ID number whenever
the program is installed on a new computer.
Because businesses and other
organizations put themselves at legal risk if they allow illegal copying and
use of software, they may be somewhat more reticent to do it than individuals.
However, individual users may feel that they can get away with it. Nevertheless,
individual users should consider that the money they pay for software goes back
into the company where it can be used for development of other programs that
may be of value to them. If everyone legally purchased their software, the
company would profit from increased sales and the price of software might well
be reduced.
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