Types of Computer Viruses And How They Work


A Virus is a computer program that has the ability to corrupt files or damage the computer system. In 2009 precisely in March, there are 10 most deadly virus names. The names of these viruses are:

1. Conficker

This sophisticated outside-tech Virus does spread out amazingly. Its form which is a DLL (Dynamic Link Library) file distinguishes it from most other viruses that are EXE. Its capabilities can also be equated with rootkits. As well, its polymorphic nature makes it have a variable body. On infected computers, users will not be able to open sites that “smell” antivirius or Microsoft update. This Virus is also actively spreading in Indonesia by using removable disk media e.g. flash disk. On the infected flash disk, you will find the Autorun. inf file and the RECYCLER directory in which there is a sub-directory with the name e.g. S-5-3-42-2819952290-8240758988-879315005-3665, and in this directory it contains a Conficker virus file With the name usually jwgkvsq. VMX which is actually a DLL file.

2. Recycler Variant

What characterizes this virus is the technique of how it spreads. Namely “Ngumpet” in the directory Recycler/Recycler/Recycle Bin. It is also known to apply the code injection technique so that the virus code can be “Nyangkut” in Explorer. exe. This is done to complicate the user or antivirus program even to kill it.

3. AutoIt variants

Almost most variants of this import-based virus script use an icon similar to a folder. This Virus has the ability to do auto update to multiple sites. He can also utilize Yahoo! Messenger as an intermediate media distribution by sending a message containing a link to each contact person in Y! M victim.

4. Yuyun. vbs

The Virus created using the Visual Basic Script is about 9KB in size. On an infected computer it will create a lot of duplicate files in each folder that he found with the filename autorun. inf, Thumb. DB, in the condition of the hidden attribute, and a shortcut with the name Microsoft. If the shortcut is accessed, it will go to a folder, but the virus behind it will also be active. The THUMB. db file Here is also not a Windows-owned file, but rather a virus script file. On infected computers will also be found a virus message file in the user’s Temp directory. In this directory will also be found other files that are virus scripts that are already in decrypt condition.

5. Vires Variant

Vires, also known as Latifah, is created using Visual Basic, in-pack using UPX. This Virus resembles an icon like a Microsoft Word document. On infected computers there will be a C: [email protected]@h. html file that contains a message from the virus maker

6. WSar. D

Like the previous variant, it is still made using VB. This variant has a size of about 108KB, pure without being in-pack. Since the icon used is a folder-like icon, while in action, it will look for a folder on every drive that is on the victim’s computer, and create a duplicate of it with the same name as the original folder.

7. Labunreke

This local Virus will hide your Microsoft Word document, MP3, JPG, and 3GP files. In addition to the victim’s computer, it will try to create some new user accounts such as Kacian, Bundrekev, and la_kalasi. At startup It will also display a message like “Congratulations, your PC is being infected. Loe data everything is safe koq, but I hide…. ^_^ “. And there are still some other jail things. So, be careful if you find an executable file that resembles WinAmp or MP3 file with a size of about 421KB.

8. Malingsi variants

A fat-built Virus with a large size, an example of one variant has a size of 705,312 bytes. It is created using Visual Basic that is pack using PECompact. It looks like this virus is aimed at attacking other viruses, this is seen from the message that is on his body. The Virus is proliferating and spreads using the mIRC intermediary, which acts as a Bot.

9. FreeMine

This local virus was created using Visual Basic with a file size of around 68KB without being in-pack. The feature of this virus, its icon resembles Microsoft Word. When he is active in memory, he will retain his survival by terminate every application that is in the Black-list list on his body, such as Process Explorer. It can also be spread via removable disk media, and on a removable disk infected there will be a file autorun. inf and Free_Mine. exe.

How computer viruses work by type. The following types of viruses and how each virus works:

1. Virus files

This Virus has a way of working that infected applications or documents in your computer. When the infected application is executed, it will spread by infecting all files or documents accessed by the application.

2. Boot Sector Virus

This Virus has a way of working that infecting the hard disk boot sector (the boot sector is an area within the hard disk that is first accessed when the computer is turned on). If this boot sector virus is active, users will not be able to boot their computer normally.

3. Virus E-mail

This Virus has a way of working which is spread by e-mail (usually in the form of file attachment/attachment). The Virus has a special feature of the. scr,. exe,. pif, or. bat extensions. If this Virus is active, then it will send itself to various e-mail addresses in the user’s address book.

4. Multipartite Virus

This Virus has a way of working that infected computer files and boot sectors on the hard drive. This type of Virus will pose many problems because it causes fatal damage.

5. Polymorfis Virus

This virus has a unique working way that the virus can change the code itself (change form) when spreading yourself to another computer Viruses are more difficult to detect because they have such properties.

6. Stealth Virus

This Virus has a way of working that he is able to hide himself by creating an infected file as if the file is not infected.

7. Macro Virus

This Virus has a working way of infecting Microsoft Office applications, such as Word and Excel. Usually documents infected by the macro Virus will modify the commands that exist in the
Microsoft Office is like the “Save” command to propagate itself when the command is executed.

Another way to minimize the virus from entering the computer is to activate user Guest and always login with the guest user. Because with user Guest then indirectly we will turn off the registry function, because the Virus will always Mangan infection this registry file and change the value in it. You can also minimize the virus into your computer by regularly updating your anti-virus.

Characteristics of computer-infected viruses.

Here are the features of a computer infected by a Virus:
1. Your computer runs slower than usual.
2. Run Menu, Search is hidden by viruses.
3. CTRL + ALT + DEL cannot be used.
4. Regedit and MSCONFIG in disabled
5. The original Folder on your computer is hidden and replaced with a virus file.
6. The Tools Menu-> Folder Options in Windows EXplorer is missing.
7. The computer often stops or does not respond.
8. The computer restarts unexpectedly or crashes and this happens a few minutes once.
9. The computer application does not run properly and often crashes.
10. Appears File with Icon Folder but has a file type. exe
11. The hard disk or disk drive can not be accessed.
12. Print activity does not work properly.
13. A strange and unusually error message is often encountered.
14. Often visible menu or dialog box is broken.
15. There is a duplicate folder name in the folder.
16. The computer always issues messages from which this virus originated.

If your computer is experiencing one of the above features, it means that your computer is infected with a virus, update your antivirus and scans your computer to clear the virus.