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Hacking Class 17 – Different Types of Virus and Worms Explained

Hey Guys Welcome back In my previous I have just named the different types of viruses. Today we are going to have a deeper look of these different types like where they store, what they damage,and how to get rid from them?? So Guys read on…

Hacking Class 17 - Different Types of Virus and Worms Explained

System Sector Viruses 

System sectors are special areas on your disk containing programs that are executed when you boot (start) your PC. System sectors (Master Boot Record and DOS Boot Record) are often targets for viruses. These boot viruses use all of the common viral techniques to infect and hide themselves. They rely on infected floppy disk left in the drive when the computer starts, they can also be “dropped” by some file infectors or Trojans.

Stealth Virus

These viruses evade anti-virus software by intercepting its requests to the operating system.
A virus can hide itself by intercepting the anti-virus software’s request to read the file and passing the request to the virus, instead of the OS. The virus can then return an uninfected version of the file to the anti-virus software, so that it appears as if the file is “clean”.

Bootable CD-ROM Virus

These are a new type of virus that destroys the hard disk data content when booted with the infected CD-ROM.
Example: Someone might give you a BOOTABLE CD-ROM.
When you boot the computer using the CD-ROM, all your data is gone. No Anti-virus can stop this because AV software or the OS is not even loaded when you boot from a CD-ROM.

Self-Modification Virus

Most modern antivirus programs try to find virus-patterns inside ordinary programs by them for virus signatures.
A signature is a characteristic byte-pattern that is part of a certain virus or family of viruses.
Self-modification viruses employ techniques that make detection by means of signatures difficult or impossible. These viruses modify their code on each infection. (each infected file
contains a different variant of the virus)

Polymorphic Code Virus

A well-written polymorphic virus therefore has no parts that stay the same on each infection.To enable polymorphic code, the virus has to have a polymorphic engine (also called mutating engine or mutation engine). Polymorphic code is a code that mutates while keeping the original algorithm intact.

Metamorphic Virus

Metamorphic viruses rewrite themselves completely each time they are to infect new executables. Metamorphic code is a code that can reprogram itself by translating its own code into a temporary representation, and then back to normal code again.
For example, W32/Simile consisted of over 14000 lines of assembly code, 90% of it is part of the metamorphic engine.

File Extension Virus

File extension viruses change the extensions of files. .TXT is safe as it indicates a pure text file. With extensions turned off if someone sends you a file named BAD.TXT.VBS you will only see BAD.TXT.If you’ve forgotten that extensions are actually turned off, you might think this is a text file and open it. This is really an executable Visual Basic Script virus file and could do
serious damage .
Countermeasure is to turn off “Hide file extensions” in Windows.

Hacking Class 17 - Different Types of Virus and Worms Explained

These are for Today .. Tomorrow we will Discuss HOW TO MAKE VIRUSES and HOW TO DO VIRUS CODING without knowing much about coding and programming language…So guys keep Reading…

About Lokesh Singh

Hello Friends, i am Lokesh Singh, certified Ethical hacker ( CEH, SSA, CSIF , CISSP). Have 8+ years of extensive experience in Ethical Hacking, Cyber Security and Penetration Testing domain.


  1. i just can’t understand why didn’t u describe ways to stop virus or neutralize virus…..u said that u were gonna help out in removing the virus….u just explained to us about the different type of virus….i appreciate that…but can u just elaborate more about detection and removal/neutralization of those c**k suc***g virus……..thnx….would b w8in for ur reply..

    hey do u know anythng about cracking of software…i cracked some softwares but i need some good tutorials on advanced cracking…thnx again…..

  2. before i am wondering why my computer fouls down, i talk to software analyst and computer expert and he found out that my computer eaten by viruses, and here i am now aware in such different viruses.

  3. thanx very nice blog

    plz gie tutorial on creating cracks,patchs and keygen of software.

  4. I am Back Guys ….
    Having a Hectic Schedule…

  5. hi!
    lokish why you are not updating the blog,
    Free ethical hacking course started on

    hurry up don,t miss newly articles

  6. Hello sir,
    this is Peeyush from Jodhpur(rajasthan).sir,i am addicted to internet..and have spend almost 1 yr in searching for new tips n tricks for hacking n cracking.I hv my own material near about 5 to 7 gb.which containing lots of advance hacking tools n software.I hv attend kyrions digital security pvt lmts hacking class.NOW QUE IS THIS WHY I AM TELLING THIS 2 YOU. Sir,i am a regular reader of ur site n i know that u r the best hacker ever.sir i want to get trained by u.i hv my questions to ask u..i wanna improve my knowledge n become expert in this field. i am engineering student.my mail id is pjrichpj@gmail.com sir plz accept my request and give a response as soon as possible..sir i again request u plz accept my request n if u like to ask smthng abt me thn plz mail me..i want my career in this field…thank u in advance.

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