What are three ways viruses are classified?

Answer 1

Resident Virus

This type of virus is a permanent as it dwells in the RAM. From there it can overcome and interrupt all the operations executed by the system. It can corrupt files and programs that are opened, closed, copied, renamed etc.

Examples: Randex, CMJ, Meve, and MrKlunky.

Direct Action Viruses

The main purpose of this virus is to replicate and take action when it is executed. When a specific condition is met, the virus will go into action and infect files in the directory or folder that it is in as well as directories that are specified in the AUTOEXEC.BAT file path. This batch file is always located in the root directory of the hard disk and carries out certain operations when the computer is booted.

Examples: Vienna virus.

Overwrite Viruses

Virus of this kind is characterized by the fact that it deletes the information contained in the files that it infects, rendering them partially or totally useless once they have been infected. The only way to clean a file infected by an overwrite virus is to delete the file completely, thus losing the original content.

Examples: Way, Trj.Reboot, Trivial.88.D.

Boot Sector Virus

This type of virus affects the boot sector of a floppy or hard disk. This is a crucial part of a disk, in which information of the disk itself is stored along with a program that makes it possible to boot (start) the computer from the disk. The best way of avoiding boot sector viruses is to ensure that floppy disks are write-protected and never starting your computer with an unknown floppy disk in the disk drive.

Examples: Polyboot.B, AntiEXE.

Macro Virus

Macro viruses infect files that are created using certain applications or programs that contain macros. These mini-programs make it possible to automate series of operations so that they are performed as a single action, thereby saving the user from having to carry them out one by one.

Examples: Relax, Melissa.A, Bablas, O97M/Y2K.

Directory Virus

Directory viruses change the path that indicate the location of a file. When you execute a program file with an extension .EXE or .COM that has been infected by a virus, you are unknowingly running the virus program, while the original file and program is previously moved by the virus. Once infected it becomes impossible to locate the original files.

Examples: Dir-2 virus.

Polymorphic Virus

Polymorphic viruses encrypt or encode themselves in a different way (using different algorithms and encryption keys) every time they infect a system. This makes it impossible for anti-viruses to find them using string or signature searches (because they are different in each encryption). The virus then goes on creating a large number of copies.

Examples: Elkern, Marburg, Satan Bug and Tuareg.

File Infector Virus

This type of virus infects programs or executable files (files with .EXE or .COM extension). When one of these programs is run, directly or indirectly, the virus is activated, producing the damaging effects it is programmed to carry out. The majority of existing viruses belong to this category, and can be classified depending on the actions that they carry out.

Examples: Cleevix and Cascade.

Companion Viruses

Companion viruses can be considered as a type of file infector viruses like resident or direct action types. They are known as companion viruses because once they get into the system they 'accompany' the other files that already exist. In other words, in order to carry out their infection routines, companion viruses can wait in memory until a program is run (resident virus) or act immediately by making copies of themselves (direct action virus).

Some examples include: Stator, Asimov.1539 and Terrax.1069

FAT Virus

The file allocation table or FAT is the part of a disk used to store all the information about the location of files, available space, unusable space etc. FAT virus attacks the FAT section and may damage crucial information. It can be especially dangerous as it prevents access to certain sections of the disk where important files are stored. Damage caused can result in information losses from individual files or even entire directories.

Examples:

Multipartite Virus

These viruses spread in multiple ways possible. It may vary in its action depending upon the operating system installed and the presence of certain files.

Examples: Invader, Flip and Tequila

Web Scripting Virus

Many web pages include complex code in order to create an interesting and interactive content. This code is often exploited to bring about certain undesirable actions.

Worms

A worm is a program very similar to a virus; it has the ability to self-replicate and can lead to negative effects on your system. But they can be detected and eliminated by anti-viruses.

Examples of worms include: PSWBugbear.B, Lovgate.F, Trile.C, Sobig.D, Mapson.

Trojans or Trojan Horses

Another unsavory breed of malicious code are Trojans or Trojan horses, which unlike viruses do not reproduce by infecting other files, nor do they self-replicate like worms. In fact, it is program which disguises itself as a useful program or application.

Logic Bombs

They are not considered viruses because they do not replicate. They are not even programs in their own right but rather camouflaged segments of other programs. They are only executed when a certain predefined condition is met. Their objective is to destroy data on the computer once certain conditions have been met. Logic bombs go undetected until launched and the results can be destructive.

Besides, there are many other Computer Viruses that have a potential to infect your digital data. Hence, it is a must that you protect your data by installing a genuine quality anti-virus software.

Answer 2

Types of Computer Viruses

1

Computer Viruses are classified according to their nature of infection and behavior. Different types of computer virus classification are given below.

• Boot Sector Virus: A Boot Sector Virus infects the first sector of the hard drive, where the Master Boot Record (MBR) is stored. The Master Boot Record (MBR) stores the disk's primary partition table and to store bootstrapping instructions which are executed after the computer's BIOS passes execution to machine code. If a computer is infected with Boot Sector Virus, when the computer is turned on, the virus launches immediately and is loaded into memory, enabling it to control the computer.

• File Deleting Viruses: A File Deleting Virus is designed to delete critical files which are the part of Operating System or data files.

• Mass Mailer Viruses: Mass Mailer Viruses search e-mail programs like MS outlook for e-mail addresses which are stored in the address book and replicate by e-mailing themselves to the addresses stored in the address book of the e-mail program.

• Macro viruses: Macro viruses are written by using the Macro programming languages like VBA, which is a feature of MS office package. A macro is a way to automate and simplify a task that you perform repeatedly in MS office suit (MS Excel, MS word etc). These macros are usually stored as part of the document or spreadsheet and can travel to other systems when these files are transferred to another computers.

• Polymorphic Viruses: Polymorphic Viruses have the capability to change their appearance and change their code every time they infect a different system. This helps the Polymorphic Viruses to hide from anti-virus software.

• Armored Viruses: Armored Viruses are type of viruses that are designed and written to make itself difficult to detect or analyze. An Armored Virus may also have the ability to protect itself from antivirus programs, making it more difficult to disinfect.

• Stealth viruses: Stealth viruses have the capability to hide from operating system or anti-virus software by making changes to file sizes or directory structure. Stealth viruses are anti-heuristic nature which helps them to hide from heuristic detection.

• Polymorphic Viruses: Polymorphic viruses change their form in order to avoid detection and disinfection by anti-virus applications. After the work, these types of viruses try to hide from the anti-virus application by encrypting parts of the virus itself. This is known as mutation.

• Retrovirus: Retrovirus is another type virus which tries to attack and disable the anti-virus application running on the computer. A retrovirus can be considered anti-antivirus. Some Retroviruses attack the anti-virus application and stop it from running or some other destroys the virus definition database.

• Multiple Characteristic viruses: Multiple Characteristic viruses has different characteristics of viruses and have different capabilities.

Answer 3

The viruses can be classified into seven different ways. They include Structure-based virus classification, Baltimore classification, Holmes classification, LHT System of Virus Classification, and Subviral agents,

Answer 4

if you have fun inside some place

Answer 5

Nucleic acid

Answer 6

internet,