50,000 computer viruses created with approximately 500 always
Some Viruses can Crash your PC.
People have a very general view that
there are many types of computer viruses and are those programs that cause damage or make the system
Malicious code is the general word used and virus is one type of
malicious code. Worms and Trojans are different from computer virus and destructive types of worms are sometimes
termed as internet types of virus. Computer viruses have made their mark on the PC's since the 90's with different
types of viruses causing damage to computers.
The earliest viruses made the most impact as no anti-virus programs were available.
The advent of anti-virus programs spelled a death blow to many common types of computer viruses that were written
by the various tools to generate types of computer virus. Those who were inept at programming used these various
tool to generate the virus. Devious mind always find new ways when they found that the anti-virus software's were
able to disinfect and remove the different types of computer viruses they went on to new methods and that is how
Trojans and worms came up.
There are a few main types of computer viruses and these computer virus types are
classified below depending upon the infection methods:
Boot sector/Master Boot Record Computer Virus
Means of Infection
Boot sector is that area of the computer that is accessed when the computer is turned on. A boot
sector virus infects this portion. Once the boot sector is infected the virus is loaded into memory when the
computer is turned on. This virus then infects boot sectors on floppies or other removable media Master Boot record
virus only infects the Master boot record and not the boot sector
Boot sector viruses gain complete control of the master boot record or the DOS boot sector by
replacing the operating system contents with that of its own. This allows the virus to spread fast and cause
By gaining control of the master boot record and the DOS boot sector the boot sector viruses can
sometimes hide the resources that the computer has( the floppy drive even though attached may not be
Some boot sector viruses contain instructions to redirect disk reads.
Some boot sector viruses move the master boot record to another location causing the system to crash
when it boots up. Other boot sector viruses cause damage to the master boot record
Some boot sector viruses damage the File Allocation Table (FAT) which is the index of all the files on
the drive. This causes loss of data
Other Types of Viruses
A type of computer virus that normally shares a few characteristics of worms or Trojans or other
methods used by the main types of computer viruses is differently classified. The nomenclature used is different.
We detail some of those below.
Some computer viruses appear to behave like many other viruses and sometimes more than one type.
These are hybrids and are called as multi-partite computer viruses.
These viruses are written such that it changes its code when ever it passes to another machine
so that it is difficult for an anti-virus scanner to locate them. Flaws in the program code make it easy to track
down these viruses. It is usually the encryption of the code that changes every time.
Whenever a virus attaches itself onto another file the size of the file increases and this is
indicated in the File allocation table. The stealth virus uses techniques to avoid detection by redirecting the
disk head to read another sector or alter the file size shown in the Directory listing .
VBS, BAT, PHP etc… They are also able to infect other file formats such as HTML (if the file format allows script
ActiveX & Java Applet's
Active X and Java Controls are being used in Web browsers to enable and disable sound or video
and a host of other controls. If not properly secured this is another area that virus writes use to get private
data from your computer.
Many types of viruses do more than viruses do. Some are file type viruses and then a trigger may activate a code to
make them behave like a worm. Therefore classification becomes difficult in these cases. The basic behavior of a
virus which makes it different from a Trojan is that it replicates very fast.
We can remove all Viruses, Trojans and Worms. Call: (716) 549-5143 if you have any
questions or think you have a virus.