Virus and antivirus by Ali Ahmed

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This is a presentation created by Ali Ahmed and I am uploading this so that some one can use this in a good way and hoping that the information included in this presentation is good for everyone.

This is a presentation created by Ali Ahmed and I am uploading this so that some one can use this in a good way and hoping that the information included in this presentation is good for everyone.

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  • 1. COMPUTER VIRUS
    &
    ANTIVIRUS
  • 2. COMPUTER VIRUS
    • A computer virus is a small program written to alter the way a computer operates, without the permission or knowledge of the user.
    • 3. With an ability to replicate itself, thus continuing to spread. Also, known as Malicious Software, a program that can cause damage to a computer.
  • CONT...
    • The computer viruses can damage or corrupt data, modify existing data, or degrade the performance of the system by utilizing resources such as memory or disk space.
    • 4. It may spread over a network (internet), carried it on a removable medium such as a Floppy disk, CD/DVD Drive, USB Drive.
  • CLASSIFICATION OF COMPUTER VIRUS
    • Boot sector virus
    • 5. Master Boot Record (MBR) virus
    • 6. File infector virus
    • 7. Multipartite virus
    • 8. Macro virus
  • BOOT SECTOR VIRUS:
    • Boot sector viruses generally hide in
    the boot sector, either in the
    bootable disk or the hard drive.
    • It attaches itself to the primary active partition of the hard disk that is read by the computer upon boot up.
  • MASTER BOOT RECORD VIRUS:
    • MBR viruses are memory-resident viruses that infect disks in the same manner as boot sector viruses.
    • 9. However it, infects the MBR of the system, gets activated when the BIOS activates the Master boot code.
    • 10. MBR infectors normally save a legitimate copy of the master boot record in an different location.
  • FILE INFECTOR VIRUS:
    • File Infector viruses infect program files. Normally infect executable code, such as .COM, .SYS, .BAT and .EXE files.
    • 11. They can infect other files when an infected program is run from floppy, hard drive, or from the network.
  • CONT...
    • Many of these viruses are memory resident. After memory becomes infected, any uninfected executable file that runs becomes infected.
  • MULTIPARTILE VIRUS:
    • A multipartite virus is a computer virus that infects and spreads in multiple ways.
    • 12. The term was coined to describe the first viruses that included DOS executable files and PC BIOS boot sector virus code, where both parts are viral themselves.
    • 13. For a complete cleanup, all parts of the virus must be removed.
  • CONT...
    • The term was coined, as prior to the discovery of the first of these, viruses were categorized as either file infectors or boot infectors.
    • 14. Because of the multiple vectors for the spread of infection, these viruses could spread faster than a boot or file infector alone.
  • MACRO VIRUS:
    • Macro are mini-programs which 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.
    • 15. Macro viruses infect files that are created using certain applications or programs that contain macros.
  • CONT...
    • They are platform-independent since the virus itself are written in language of the application and not the operating system.
    • 16. They infect documents created from Microsoft Office Word, Excel, PowerPoint and Access files.
  • CONT...
    • E.g.W97M.Melissa,Bablas,WM.NiceDay,W97M.Groov.
  • We Are The Angels Of Your Computer System. We Protect Your System Round The Clock
  • 17. Your Time Is Up, My Time Is Now....
  • 18. ANTIVIRUS
    • An antivirus software is a computer program that identify and remove computer viruses, and other malicious software like Worms and Trojans from an infected computer.
    • 19. Not only this, an antivirus software also protects the computer from further virus attacks.
  • CONT...
    • We should regularly run an antivirus program to scan and remove any possible virus attacks from a computer
  • ANTI-SPYWARE
    • They can provide real time protection against the installation of spywares on the computer.
    • 20. This type of spyware protection works the same way as that of anti-virus protection.
    • 21. It scans and blocks all incoming network threats as it comes across.
  • CONT...
    • It can be used solely for detection and removal of spyware that has already been installed into the computer.
    • 22. Anti-spyware scans the contents of the windows registry, operating system files, and installed programs on the computer and will provide a list of any threats found.
  • HOW AN ANTIVIRUS WORKS?
    Using dictionary Approach:
    • The antivirus software examines each and every file in a computer and examines its content with the virus definitions stored in its virus dictionary.
    • 23. A virus dictionary is an inbuilt file belonging to an antivirus software that contains code identified as a virus by the antivirus authors.
  • CONT...
    USING SUSPICIOUS BEHAVIOR APPROACH:
    • Antivirus software will constantly monitors the activity of all the programs.
    • 24. If any program tries to write data on an executable file, the antivirus software will flag the program having a suspicious behavior, means the suspected program will be marked as a virus.
  • CONT...
    • The advantage of this approach is that it can safeguard the computer against unknown viruses also.
    • 25. The disadvantage is that it may create several false alerts too.
  • VIRUS UPDATES
    • Providing regular updates for the virus dictionary.
    • 26. An antivirus program should provide free virus updates on a periodic basis.
    • 27. With the current outburst in macro and script-based viruses, virus updates that address the latest threats are essential.
    • 28. Most commercial antivirus software in today’s scenario provide virus updates on daily basis.
  • 29. WHAT TO DO IN SUSPECTING
    VIRUS ATTACK?
    • Disconnect the suspected computer system from the Internet as well as from the Local Network.
    • 30. Start the system in Safe Mode or from the Windows boot disk, if it displays any problem in starting.
    • 31. Take backup of all crucial data to an external drive.
  • CONT...
    • Install antivirus software if you do not have it installed.
    • 32. Now, download the latest virus definitions updates from the internet.
    • 33. Perform a full system scan.
  • POPULAR ANTIVIRUS &
    ANTI-SPYWARE SOFTWARES
  • 34. ANTI-VIRUS & ANTI-SPYWARE IS THE BODYGUARD OF YOUR SYSTEM.....
    IT IS US WHO RULES, NOT MALWARES.....
  • 35. Reference
    http://en.wikipedia.org/wiki/Computer_virus
    http://en.wikipedia.org/wiki/Adware
    http://en.wikipedia.org/wiki/Spyware
    http://en.wikipedia.org/wiki/Antivirus_software
    http://en.wikipedia.org/wiki/Multipartite_virus
    www.slideshare.net --- 9/27/11
    http://www.google.mv/imghp?hl=en&tab=wi
    http://tinyurl.com/3snzgs3
    http://tinyurl.com/8oz7a5
  • 36. Reference
    http://tinyurl.com/455tn3z
    http://tinyurl.com/3o28oj7
    http://tinyurl.com/3oxgcr5
    http://tinyurl.com/3fhlgd2
    http://tinyurl.com/3nxb6rh
    http://tinyurl.com/3hkd39m
    http://www.slideshare.net/leeb2/how-to-avoid-infections-on-your-computer-that-is
    http://www.slideshare.net/mikee28/computer-virus-5640866