Types Of Virus

To further refine our knowledge about the virus, I'll try
provide an explanation of the types of viruses that often roam
in the cyber world.

1.Virus Macro
This type of virus must have been very often we are Listen.Virus 
with the programming language of an application rather than by language
programming of an Operating System. This virus can walk if
constituent applications can run well, that if the
mac computer can run the application of this word then the virus works on
 computer. with Mac OS system. 
virus samples:

W97M-variant, for example W97M.Panther
1234 bytes long,
  Will Infect Normal.dot and infect the document when opened. 
-WM.Twno.A; TW
41,984 bytes long,
Ms.Word document will infect that use macro languages, usually
  DOT and Have extension *. DOC *. 
-etc

2.Virus Boot Sector
Boot sector virus is very common in doubles SPread.Virus 
he will move or replace the original boot sector with the program
boot virus. So when there is booting the virus will be loaded to memory 
and then the virus will have the ability to control the standard hardware
(ex:: monitor, printer, etc.) and from this memory is also the virus will spread
to all existing drives and connected to computer (ex: floppy, drives 
other than drive c).
virus samples:

-wyx virus variants
ex: wyx.C (B) to infect the boot record and floppy;
length: 520 bytes;
characteristics: memory resident and encrypted)
-variant V-sign:
infect: Master boot record;
520 bytes long;
characteristics: living in the memory (memory resident), encrypted, and polymorphic)
-Stoned.june 4th / bloody!:
infect: Master boot record and floppy;
520 bytes long;
characteristics: living in the memory (memory resident), encrypted and display
message "Bloody! june 4th 1989" after booting the computer as much as 128 times

3.Stealth Virus
This virus will dominate the table with DOS interrupt table that often we know
with "Interrupt interceptor". These viruses capable of controlling
DOS level instruction instructions and they are usually hidden as its name
either in full or in size.
virus samples:
-Yankee.XPEH.4928,
infect files *. COM and *. EXE;
4298 bytes long;
  characteristics: settled in memory, SIze is hidden, has a trigger 
-WXYC (which includes any category because the boot record into stealth category 
  also included here), to infect the floppy motherboad record; 
520 bytes long;
settled in memory; size and hidden viruses.
-Vmem (s):
infects files *. EXE, *. SYS and *. COM;
fie 3275 bytes long;
characteristics: living in memory, the size of the hidden, in the encryption.
-etc

4.Polymorphic Virus
The virus is designed for misleading antivirus program, meaning the virus is always
trying to avoid being recognized by the anti-virus is always changing by the fox
structure after each infects files / other programs.

virus samples:

-Necropolis A / B,
infect files *. EXE and *. COM;
file 1963 bytes long;
  characteristics: settled in memory, the size and viruses is hidden, encrypted and 
can be changed to change the structure
-Nightfall,
infect files *. EXE;
file 4554 bytes long;
  characteristics: living in memory, the size and viruses is hidden, has a trigger, 
  with encript can change the structure 
-etc


5.Virus File / Program
This virus infects files that can be executed directly from the operating system,
good application file (*. EXE), or *. com infections usually also result
of this virus can be identified by changing the file size is attacked.


Partition 6.Multi Virus
This virus is a combination  from Virus and boot sector viruses File: means 
the work performed resulted in two, that he can infect a file -
*. EXE file and also infect the Boot Sector.
Read also other article about computer virus:
The origin Virus  
Definition of Virus  
Character and Criteria   
Virus life Cycle