Computer virus and Prevention
recent years, through the transmission of e-mail, virus has become
the biggest hazard to the development of the network industry. Since the past
few years, a wide range of viruses have been spread through internet. As the
internet is becoming a global tool, the virus is also becoming a global trouble
maker, and system killer. Compared with the traditional virus, the viruses
spread through the network, especially the e-mail, shows faster speed and more
powerful lethality. On the basis of
analyzing the characteristic of the computer virus in the information
technology age, the effective way of preventing virus will be discussed.
1 The Generation of Computer Virus
The generation of computer virus is the inevitable
product of the development of computer technology and the process of computer
based social information development to a certain stage. The background is:
is computer virus?
Computer virus is a new form of high technology crime,
which is instantaneous, dynamic and random. It is
essentially difficult to obtain evidence, and it can damage the computer
dramatically. Because it has small risk and huge damage, it irritates the crime
consciousness and criminal activity. It reflects some people’s mischievous and
retaliatory mindset in the field of computer application.
The technical reason is the vulnerability of the
software and hardware of the modern computer. The software could be easily
deleted or rewritten. And, the manual way to design the computer software is
inefficient and not secured, due to its long production cycle. Designer have no
way to know whether there is any mistake in the program before the program is
in operation. The mistake could be modified only in the operation. Designers
have no idea how many errors and defects are hidden in the program. Those
vulnerabilities provide a tunnel for the invasion of the virus.
The popularization of computers is the necessary
environment of the generation of computer virus. The hardware of most of the
modern computers is simple, and the operation system is highly transparent. Due
to the lack of security, more and more users are able to understand clearly the
shortcoming of the computer. They could make
different attack choices based on different purposes.
Properties of computer virus
Computer virus can be hidden in computer storage
medium (the hard drive) or program. When certain condition is qualified, the
computer virus is activated by some program, or instructed remotely to destroy
computer resources. The computer virus is a small program, but it is different
from the computer program with some unique characteristics
computer virus is parasitic in another program. When executing this program,
the virus will begin to destroy; however, it is not easy to be detected before
computer virus can not only destruct, but also infect. The infection speed is
hard to contain once the virus is produced and duplicated. In the biology
world, virus spread from one organism to another through infection. Under
appropriate conditions, it can be reproduced in large quantities, and wells
make the infected organisms show illness or even death. Similarly, computer
viruses will spread from infected computers to non-infected computers through
In some cases, the infected computers will be in disorder or even
paralyzed. Unlike the biological virus, a computer virus is a piece of human
generated computer program, that can be transferred to other computers. Once
the program is executed, it will search for other program or storage medium
containing infectious conditions. It will determine the target and them
insert its own code into another program
to achieve the purpose of self reproduction. If a computer is infected, if it
is not processed in time, the virus will spread quickly on this machine, and a
large number of files (usually executable files) will be infected. The infected
documents have become a new source of infection, and then infect other machines
or contact them through the network, the virus will continue to spread. Normal
computer programs generally do not connect their own code to other programs.
The virus can force its own code to infect all non-infected programs. Computer
viruses can infect other computers through various possible channels, such as USB,
and computer networks. When a computer virus is found on a machine, the carrier
that is used to transfer files is also infected. Other computers that are in the same network
as the infected computer may also be infected by the virus, too. Whether it is
contagious or not is the most important condition for judging whether a program
is a computer virus.
viruses, like a time bomb, make it predesigned at any time. For example, the
black Friday virus can’t be detected at any time before the scheduled time.
When the condition is available, it will explode at once and destroy the
system. A compilation of sophisticatedcomputer virus program, enter the system
after the general can not immediately attack, in a few weeks or months or years
hidden in the legal document, to spread to other systems, without being found,
latent in the system is better, the time will be longer, infectious the greater
the scope will be virus. The first kind of latent virus program refers to, no
special test procedure is not check out, so the virus can quietly hide in the
disk as carrier for a few days, or even years, once the time is ripe, it will
get a chance to run, reproduce and spread, continue to damage. The second
manifestation of latency is that there is usually a trigger mechanism inside
the computer virus. When it does not meet the trigger condition, the computer
virus will not destroy anything besides infection. Once the trigger condition is
satisfied, some display information, graphics or special marks on the screen,
others perform operations that destroy the system, such as formatting disk,
deleting disk files, encrypting data files, blocking keyboards, and locking the
virus has a strong concealment, some can check out the virus software, and some
simply do not check out some hidden, constantly changing, this kind of virus
treatment usually very difficult.
when a computer is poisoned, it may cause the normal program to be unable to
run, delete the files in the computer or be damaged in varying degrees.
virus, due to the occurrence of an event or value, enticing the virus to carry
out infection or attack is called triggering. In order to concealment, the
virus must lurk and do less. If it is completely inactive and lurking, the
virus can neither infect nor destroy it, and it loses its lethality. The virus
needs to be hidden and killed, and it must be triggered. The triggering
mechanism of a virus is used to control the frequency of infection and
destruction. The virus has a predetermined trigger condition, which may be
time, date, file type, or certain data. When the virus is running, the trigger
mechanism checks whether the predetermined conditions are met, if it satisfies,
it starts the infection or destruction action, so that the virus is infected or
attacked. If it is not satisfied, the virus will continue to lurk.
The most common computer virus
and their forms at present (for Windows only) TODO
Computer Virus Precaution strategy
most important hardware and software entities in the computer network are
servers and workstations. Therefore, the server and the workstation should be
considered the first for prevention and control of computer network viruses. On
the other hand, strengthening comprehensive control is also important. The
network server is the center of the computer network, and it is the backbone of
the network. One of the important signs of network paralysis is the paralysis of
the network server. Once the network server is knocked down, the loss is
catastrophic, irretrievable, and inestimable.
of local area network virus: virus prevention has became a very important part
of the daily management of the local area network (LAN) in the company, due to
the huge number of computers in LAN and the users are on different level of
anti-virus. Therefore, the prevention of computer virus should qualify the
It is essential to select the anti-virus software
application and update the virus database.
Install all kinds of patches, timely installation of
various patches is also very important
Standardize the use of
Do backup for
work and data. To a company, the most important part should be the files and
data in the storage
Isolate the infected computer
on the user end
Pay attention to the attachment of the mail as much as
Always in a set of anti-virus software.
Pre scan the accessories before opening any attachment
Pay attention to the file extension. Windows allows
users to use multiple extensions when naming files, but many e-mail programs
display only the first extension. This will camouflage the virus.
Do not run unknown program
Never blind forward any email
Blocking system vulnerabilities. Many network viruses
are now spread with Microsoft’s IE and Outlook’s vulnerabilities.
Don’t take the documents casually. Try not to accept
files from strangers in the online chat system, such as Skype or Facebook.
Do automatic virus check to ensure that the computer
will do automatic virus check on the inserted plug and play media, as well as
e-mail and internet files.
network security strategy
network security strategy: TODO
encryption strategy: TODO