LOBO7 “CYBER VIRUS COURSE” BASIC
What is a Cyber Virus ?
A Cyber Virus is an executable program code that has
the ability to replicate itself numerous times very quickly. It can attach
itself to any kind of file and spreads itself as a file that is
copied.
The replication in itself is not
the main problem, but the damage routine that can be delivered by the Virus
payload.
Payloads can display images,
messages, selectively destroy files, reformat several drives or any other
damaging programming request.
Joke Viruses
don’t have a damaging routine, but they still affect your computer’s
performance by taking up storage space or memory (ex. Virus “Spawn”) when it
replicates itself. This will definitly downgrade the overall performance of your
system.
How does a Cyber Virus spreads ?
Not so long ago, Cyber Viruses were spread via floppy
disks or any other external peripheral that was portable and could be used on
another computer.
Nowadays, the Internet
has given the Cyber Viruses a “speed of light” spreading capability being the
E-Mail system a very important communication tool for private or business
use.
Within minutes, an infected E-Mail
can bring a Company down, causing costly productivity loss and clean-up
expenses.
There are more than 50.000 known
Cyber Viruses and an average of at least 100 are created every month.
Cyber Viruses won’t go away any time soon and they
affect every Computer user directly or indirectly.
Keeping these numbers in mind, it is safe to assume that all
organizations using Computers, will deal with Cyber Virus outbreaks from time to
time.
How do you minimize the possibilities of being attacked by a Cyber Virus ?
It is very important that you keep your Anti-Virus
Software as updated as possible, but this will give you only half the
protection, the other half is being an educated Computer user (Safe
practices) and User common sense.
It
is very important that you always remember that having an updated Anti-Virus
program does not give you 100% automatic protection.
To start with, there is a time window from when a Virus is
released to when the update is available.
During this time frame, the PC user is a “sitting duck” having as
only protection his common sense.
You can
compare the Internet to walking in a big city at night. You can be relatively
safe but you have to be alert and caucious.
Ultimately what will help control these kind of disasters is
not technological wizardry but the Cyber equivalent to “Street Smart”.
What are the known Cyber Virus types at the moment ?
There are four known main classes :
Boot Sector Viruses
File Infecting Viruses
Multi-Partite Viruses
Macro
Viruses
What is a Boot Sector Virus ?
A few years ago , they were the most prevalent
viruses. They use the 16-bit DOS to infect the Boot Sector of a floppy disk and
then this floppy disk will infect the Master Boot Record (MBR) and the hard
drive.
Once the MBR is infected, the Virus
will attempt to infect the Boot Sector of every floppy disk that is used and
accessed with this computer.
The Boot
Sector Virus hides itself on the first sector of a disk. This is how the Virus
is loaded into memory before the System files. This procedure allows the Virus
to gain complete control of DOS interrupts making the spreading
easier.
It is common practice that a Boot
Sector Virus replaces the original contents of the MBR or DOS boot sector with
their own contents and also moves the sector to another area in the
disk.
The cleaning of a Boot Sector Virus
can only be done by booting the affected Computer with an uninfected floppy
System Disk or by finding the original Boot Sector and moving it to the correct
location on the Disk.
What is an File Infecting Virus ?
They are also known as Parasite Viruses and operate
normally in the memory.
The files that
these Parasite Viruses target are normally executable files with extensions as
:
COM, EXE, BAT, SCR, PL, DRV, DLL, BIN, OVL,
SYS.
The Parasite Virus is activated every
time the infected file is executed, it can normally copy itself into other
executable files and can remain in the memory long after the
activation.
There are thousand of File
Infecting Viruses, some of them operate in a DOS 16-bit environment and some
operate in Microsoft Windows, IBM OS/2, and Apple Computer Macintosh
environments.
What is a Multi-Partite Virus ?
They have the characteristics of both: Boot Sector
Viruses and File Infecting Viruses.
What is a Macro Virus ?
Macro Viruses infect the Macro utility that accompany
applications.
Besides being the fastest
growing Viruses in computer history, they represent most probably 80 percent of
all the known Viruses.
Macro Viruses are
Application specific but not Operating System specific.
Being Application specific means that a Word Macro Virus cannot
infect an Excel file and vice versa.
They
can be spread by E-mail attachments, floppy disks, Web downloads, file transfers
and shared applications.
Macro files are
written in Visual Basic and the infection can occur at different points during
the use of the file, for example ; when opened, saved, closed or
deleted.
Description of the Life Cycle of a Cyber Virus.
The Creation
In the past, only a programmer could create a Cyber Virus but
nowadays with the help of all the conveniences and tools available, anybody with
a little bit of programming knowledge can create one.
A lot of known Cyber Viruses are just an improved “cut &
paste” version of former Cyber Viruses.
Cyber Viruses are usually created by misguided individuals who
wish to cause widespread damage and gain recognition between their
peers.
The Replication
Viruses replicate to spread themselves. A well-designed virus will
replicate for a long time before it activates, which allows it plenty of time to
spread before being detected.
The Activation
Viruses with damaging payloads will activate when the condition
that was set is met, for example, a date condition or an action
condition.
The Discovery
This phase doesn’t necessarily happen after activation.
When detected and isolated, it is sent to the
International Computer Security Association in Washington, D.C., to be
documented and distributed to antivirus developers.
The Assimilation
At this point, the corrective update is developed by the
Anti-Virus Developers.
This can take
anywhere from a couple of hours to several days, depending on the developer and
the virus type.
The Eradication
Eradicating a Cyber Virus is very difficult but having updated
Anti-Virus Software, safe computer practices and User common sense will
certainly make a Cyber Virus cease to be a major threat to the Cyber
Community.
BE ALERT….COMMON SENSE…..AND STAY SAFE..!!
“HELP KEEP THE NET CLEAN”