Presentation on computer virus, Assignments of Computer Science

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COMPUTER

VIRUS

Team

Ali Asad

Hajra Ansar

Khizar Nadeem

Noor Ul Ain Naveed

Shahmeer Aulakh

DAMAGE TO THE

COMPUTER

• (^) A computer virus can damage data or software on the computer.
• (^) It can delete some or all files on the computer system.
• (^) It can destroy all data by formatting hard drive.
• It may detect some special information like passwords.
• It may slow down the speed of the computer system.
• (^) It may display a political or false message every few times.
• (^) A virus may also make some resources unavailable to the users.

CAUSES OF COMPUTER

VIRUS

• (^) Email The viruses are most commonly spread through emails. An email may contain an infected file attachment. Viruses can spread if the user opens and downloads an email with infected file.
• (^) Networks Virus can spread if the user connects with a computer network that contains virus. Internet is an example of such network. When a user downloads a file infected with virus from internet, the virus is copied to computer, It may infect the files stored on the computer.
  • Removable Storage Media Flash drives and CDs are important means of exchanging data. A virus can also be copied from one computer to other when the user copied infected files using these devices.
  • (^) Pirated Softwares The illegal copy of software is called pirated software. Virus can spread if the user installs pirated software that contains virus. A virus of pirated software is available in CDs and from Internet. Some companies intentionally adds virus in the software. The virus is automatically activated if the user uses the software without purchasing license.

PROTECTION OF

COMPUTER SYSTEM FROM

A VIRUS

• The latest anti-virus should be installed on computer.
• The Antivirus software must be upgraded regularly.
• The floppy disk should be scanned for viruses before use.
• Junk or unknown emails should not be opened.
• Unauthorized or pirated software should not be installed on computer. - An important way of protection against virus is the use of backup of data. The backup is used if the virus deletes the data or modifies it. - (^) Freeware and shareware software from the internet normally contain viruses. It is important to check the software before using them.

TYPES OF VIRUSES

• Boot Sector Virus
• (^) Chernobyl Virus
• (^) Logic Bomb
• (^) Trojan Horse
• (^) Redlof

CHERNOBYL VIRUS

The famous Chernobyl virus deletes all Microsoft Office files. It also deletes files partition information from the disk tha causes a major loss of data. It also corrupts the system’s BIOS.

LOGIC BOMB

Logic bomb is a virus activates when certain conditions are met such as opening a file or when certain date and time occurs etc. It is also called time bomb. Michelangelo is an example of logic bomb. It destroys data on the hard disk on March 06.

REDLOF Redlof is a polymorphic virus. It is written in Visual basic Script. It relies on the Microsoft ActiveX Component to execute itself. It locates Folders.htt and infects that file Folder.htt is part of Microsoft Windows Active Desktop feature.

ANTIVIRUS SOFTWARE A type of software that is used to detect and remove viruses is called antivirus software. Antivirus programs contain information about different known viruses. They can detect viruses and remove them. Many antivirus programs are available in market. But no single software can detect and remove all viruses. Many new viruses are invented and spread through Internet continuously. Antivirus programs are also upgraded continuously to detect these new viruses. Antivirus program not only detects viruses from computer but also prevent new viruses. Antivirus program not only detects viruses from computer but also prevent new viruses from entering into the computer. Examples  (^) Norton Antivirus  (^) Kaspersky  (^) McAfee  (^) AVG  (^) NOD