|
|
Viral infection in men and
animals, a major cause of morbidity and mortality, particularly in developing
countries, has been reported for centuries.
Epidemics of yellow fever virus have constituted major public health problems in many countries, including Nigeria, in the recent past. As doctors and other health workers are familiar with signs and symptoms of various viruses, features of computer viruses should be known to computer users.
The problem with computer viruses,
a bug that causes system software to malfunction, has escalated since 1985
from a mere handful to many hundreds, with dozens of new ones appearing every
month. The damage they can do is increasing
too as viruses which target specific informations, such as network passwords,
are starting to appear.
Most establishments are not
adequately prepared to deal with the consequences of infections or other attacks
on their computer systems. Because
of this, the damage caused by the virus is epidemic in nature. A virus, once activated spreads continuously,
and could be very difficult to eradicate. Viruses destroy data, affect hardware and make
programs malfunction as they proliferate.
They unleash long term and paralytic effects on systems.
The Viruses can be contacted
by using unlawfully copied or modified programs on computer system. They are then passed to each uninfected program
that comes in contact with the infected host.
Many viruses are now specifically
programmed to perform some function outside of self-replication.
This function, called the payload, can be as innocuous as displaying
a message on the computer’s monitor or as harmful as destroying data on the
system’s hard disks.
Often, one of the actions of a virus is to check the system’s time and date. It will also check if there are other unifected and accessible files or disks. If it finds any, it infects them immediately, and if not, it passes control to the operational system, remaining dormant in memory until a favourable infection or activation opportunity arises.
Even the virus experts themselves
can have problems. U.K specialist
Jim Bates is reported to have accidentally triggered a virus,
Datacrime 2, when he hit the wrong button at the wrong time and in effect,
lost 44mb of data and programs.
In 1989, the British Royal
National Institute for the blind lost important records because of virus activity.
Many institutions and individuals have suffered similar damages.
Some viruses are relatively benign, limiting themselves to flashing
some characters on the screen, playing music or other similar relatively harmless
activities.
Others are much more dangerous
and can lead to a partial or total loss of data by deleting files, over-writing
files, or even performing a low-level format of an entire disk.
Many viruses slow down the computer system by the sheer load that their
reproductive ability imposes; especially when there are bugs in its reproductive
process. Others can spoil disk drives by making them
to spin excessively, or spoil the clock mechanism by forcing the clock to
go faster.
Viruses spread very rapidly
merely through the use of pirated programs, free diskettes distributed for
demonstration purposes, or infected software loaded over telephone lines via
MODEM. In principle, a diskette used
in large number of Computers is likely to pick up a virus from one of them
and pass it on to the others.
The conceptual foundations
for computer viruses, which are categorized on the basis of their mode of
infection, have been around much longer than the virus threat itself.
Although virus historians disagree
on the specific whens and wheres, it is generally accepted that the idea was
born when computers were still huge and expensive-the domain of large corporations
and the government, not the public. Also, while many of the viruses circulating today are malicious,
destruction of data was not part of the original premise.
The idea was that if one could
create a computer program that could make copies of itself, or self replicate,
it might also be possible for that program to evolve. If an error were to occur in the replication
process, the resulting code (the bits of information that make up the program
would be mutant. Just as mutant genetic
code is what disposes a biological virus to either be more or less able to
survive and propagate, mutant digital code might dispose a computer virus
to be more or less a computer virus to be more or less able to survive in
the computer environment).
One of the first known viruses
was written in 1983 by Fred Cohen, a student at the University of Southern
California, whose doctoral dissertation showed how computer code could clone
itself and attach to other programs, thereby causing them to execute in a
different way.
Some virus writers actually
choose to identify themselves; such as the Pakistani brothers who wrote the
Brain virus. The brothers included
the name, address and telephone number of their software company in the viral
code.
Other virus writers are disgruntled
employees seeking revenge, while others are school kids who write just to
see if they can. Whatever the motivation,
the number of people capable of writing a virus is growing right along side
the computer industry.
Those who stand to be affected
by virus infection – anyone who uses computer – should be alert and wary.
The presence of these viruses can also be deduced from the telltale
increase in the size of infected files to which they have attached themselves.
Some of the most common of
the over 20,000 Viruses are AIDS, Alabama, Alameda, Black Avenger, Bulgarian,
Cascade, Columbus Day, Christmas, Dbase, Devil’s Dance, Disk Killer, Frodo,
Jerusalem, Fu Manchu and Ghost Viruses.
Others include Itavir, Ping-Pong,
Saturday 14th, Stoned Marijuana, Sunday, V2000, Yale, Yankee Doodle
and the 1260 viruses.
This involves the implementation
of rules and procedures, as well as increasing the users’ awareness.
The procedures include:-
Ř Prevention of pirated software
on the system.
Ř Scanning of any diskette to
be used on the computer.
Ř Non-allowance of unauthorized
programmes, especially games or anything that has come from an educational
establishment.
Ř Write-protect the diskette
you are not intending to write on.
Ř Restrictions of the use of
systems to only the company staffs who are charged with such duties.
Ř Most modern computers, in particular
PCs have key. Such facilities must
be used when systems are not in use.
Ř Create passwords that allow
only authorized users access to your system.
Also, IBM reference diskettes usually come with password.
Ř Change the password as often
as possible.
Ř Install encapsulated systems,
which allow users to access only the part of the system that they need to
assess.
Ř Cover up systems with dust
cover when not in use. Systems are
very sensitive to dust.
Ř If a virus does strike and
softwares are damaged, there is no need to panic if the back-up or “Original”
Software is available and well secured. Make
a back up of all data or softwares because of infection of the original.
Ř The use of disk bank to store
diskettes should be encouraged. This
will prevent unauthorized persons from tampering with your disks and the information
stored therein.
Ř Write-protection of all diskettes
containing important softwares.
Computer and Information Management
Centre (COINMAC INT’L. LTD.) Ibadan