2. THIS IS A POWERPOINT PRESENTATION FOR THE TOPIC VIRUS SUBMITTED BY : ROHIT SHRESHTHA UNDER THE GUIDANCE OF MY FACULTY Mr. DATTATREYA JOSHI

3. content Virus Major Areas Of VIRUS Attacks Types Of Viruses
Simple Things You Can Do To Protect Your Computer
Anti-virus And Its Various Types
What To Look For In An Anti-virus Software
Endnote

4. VIRUS
The term virus is often mistakenly used to describe any malicious code (malware).
To understand what is a virus first we need to know what is a malware ?
MALWARE
Malware is a term that is used for malicious software that is designed to do damage or unwanted actions to a computer system.
While many computer users face the threat of malware, understanding the different types and how they affect users is essential to protecting against scams and ensuring security for online operations.
Major malware include the following:
Virus , Worms & Trojan Or Trojan Horse

5. Virus Internet Hacker B PROTECT HOSTS TIME BOMBS Antivirus VECTORS
DETECT
HOSTS
Attack
TIME BOMBS
Virus
Antivirus
Trojan horse
VECTORS
Worms
detection
LOGIC BOMBS
MACROS VIRUS
MALWARE
Preventive
measures
Anti -Virus
Internet B
Hacker
Networks .
BOOT SECTOR VIRUS
PROTECT

6. VIRUS

7. Virus
A virus is a program or a small piece of programming code that attacks computer & network systems through ‘contaminated ‘( infected ) files .
Virus are introduced into a system via attachments ; external storage devices ; or downloads from Internet ,
A computer virus attaches itself to an executable file (host file) in computer. A virus can reside in the computer but it cannot infect the computer unless the host file is opened allowing the virus to intrude the system .

8. Virus
After opening of host file virus loads itself into the computer & starts replicating by creating copies of itself and attaching those copies to other files in the system .
A virus cannot infect and spread through computer systems without any action from the user. A virus can reside in the computer but it cannot infect the computer unless the host file is opened by a user .

9. WORMS

10. Worm
A worm is technically not a virus, but a program very similar to a virus; it has the ability to self-replicate
Computer worms replicate copies of themselves and damage host programs in a similar way to viruses, they may be more dangerous as they can infect and spread through computer systems without any action from the user.
i.e. worms can operate on their own and spread by exploiting vulnerabilities within the victim’s operating system.

11. Worm
Due to the copying nature of a worm and its ability to travel across networks the end result in most cases is that the worm :
consumes too much system memory in the computer system ;
consumes too much network bandwidth .
This causes Web servers , Network servers and individual computers to stop responding and networks grind to a halt.

12. TROJAN HORSE

13. TROJAN or TROJAN HORSE
Trojans are named after the ancient Greek historical story of the wooden horse gifted to TROY so as to unknowingly allow Greek soldiers (hidden inside the wooden horse) to pass through the protective walls of troy and take over the city .

14. TROJAN or TROJAN HORSE
The nickname is appropriate, as Trojan malware software seems safe enough to install that users voluntarily install them onto their computers, allowing the malware to infect their systems .
A Trojan horse program has the appearance of having a useful and desired function however secretly the program performs other undesired functions like stealing data , deleting files or compromising a system by providing a means for another computer to gain access .

15. TROJAN or TROJAN HORSE
Some Trojans are designed to be more annoying than malicious (like changing your desktop, adding silly active desktop icons)
They can cause serious damage by deleting files and destroying information on your system.
Trojans can also create a backdoor on your computer that gives the malicious users access to your system, allowing confidential or personal information to be compromised

16. Are Virus , Worms & Trojan Horse All Same ?

17. Are Virus Worms & Trojan Horse All The Same ? NO
Computer virus replicate copies of themselves and damage host programs . A virus cannot infect and spread through computer systems without any action from the user. A virus can reside in the computer but it cannot infect the computer unless the host file is opened by a user .
The task of a virus is not always destructive like deleting files that may be important or something like
causing your hard drive to crash. Many viruses these days are more interested in harvesting information
from your computer and or using it as a zombie for their intentions like spam or other illegal purposes.

18. Are Virus Worms & Trojan Horse All The Same ? NO
Computer worms replicate copies of themselves and damage host programs in a similar way to viruses, but can infect and spread through computer systems without any action from the user.
worms consumes too much system memory in the computer system and network bandwidth
This causes Web servers , Network servers and individual computers to stop responding and networks grind to a halt.

19. Are Virus Worms & Trojan Horse All The Same ? NO
Strictly speaking, a Trojan horse is a malware but not a virus or worm because it neither replicates nor copies itself, but causes damage or compromises the security of the computer

20. Major Areas Of Virus Attacks
Binary executable files (such as COM files and EXE files in MS-DOS, Portable Executable files in Microsoft Windows, the Mach-O format in OSX, and ELF files in Linux)
Volume Boot Records of floppy disks and hard disk partitions
General-purpose script files (such as batch files in MS-DOS and Microsoft Windows, VBScript files, and shell script files on Unix-like platforms).

21. Major Areas of Virus Attacks
Application-specific script files (such as Telex-scripts)
System specific auto run script files (such as Autorun.inf file needed by Windows to automatically run software stored on USB Memory Storage Devices).
Documents that can contain macros (such as Microsoft Word documents, Microsoft Excel spreadsheets, AmiPro documents, and Microsoft Access database files)

22. Major Areas of Virus Attacks
The master boot record (MBR) of a hard disk
Arbitrary computer files. An exploitable buffer overflow, format string, race condition or other exploitable bug in a program which reads the file could be used to trigger the execution of code hidden within it.
Cross-site scripting vulnerabilities in web applications .

23. Types Of Virus VIRUS Virus can be classified on the basis of
1 . What do they infect ?
How do they infect ?
Boot Sector Virus
Direct Action Viruses
Directory Virus
Virus
Fat Viruses
Macro Viruses
VIRUS

24. Types Of Virus VIRUS Memory Resident Viruses Root kit Virus
Non Resident Virus
Companion Virus
Stealth Viruses
Multipartite Viruses
Overwrite Viruses :
Polymorphic Viruses
VIRUS

25. Types Of Virus
Boot sector Virus: A virus which attaches itself to the first part of the hard disk that is read by the computer upon boot up. These are normally spread by floppy disks.
Direct Action Viruses : When a certain condition is met, the viruses will act by infecting the files in the directory or the folder specified in the AUTOEXEC.BAT. The viruses are generally found in the hard disk’s root directory, but they keep on changing location.

26. Types Of Virus
Directory Virus : Also known as cluster virus or file system virus. They infect the computer’s directory by changing the path indicating file location. They are usually located in the disk but affect the entire directory.
Virus : This is a virus spread via an . Such a virus will hide in an and when the recipient opens the mail.

27. Types Of Virus
FAT Viruses : These lardy viruses attack the file allocation table (FAT) which is the disc part used to store every information about the available space, location of files, unusable space etc.
Macro Virus: Macro viruses are viruses that use another application's macro programming language to distribute themselves. They infect documents such as MS Word or MS Excel and are typically spread to other similar documents.

28. Types Of Virus
Memory Resident Viruses : They usually fix themselves inside the computer memory. They get activated every time the OS runs and end up infecting other opened files. They hide in RAM.
Root kit Virus : A root kit virus is an undetectable virus which attempts to allow someone to gain control of a computer system. The term root kit comes from the Linux administrator root user. These viruses are usually installed by Trojans and are normally disguised as operating system files.

29. Types Of Virus
Companion Viruses : These types of viruses infect files just like the direct action and the resident types. Once inside the computer, they ‘accompany’ other existing files.
Multipartite Virus : These type of viruses spread in many different ways. Their actions vary depending on the OS installed and presence of certain files.

30. Types Of Virus
Overwrite Viruses : These types of viruses delete any information in a file they infect, leaving them partially or completely useless once they are infected.
Polymorphic Virus : They encode or encrypt themselves in a different way every time they infect your computer. They use different encryption and algorithms. This makes it difficult for the antivirus software to locate them using signature or string searches

32. Simple Things You Can Do To Protect Your Computer
Never open from unknown sources
Don't open unknown attachments in s or do a virus scan after opening them. 
You should have a backup system that is separate from your computer's own hard drive for all of your important documents, music, and other data.
This may be an external hard drive with backup software, a cloud storage solution like Drop Box or a dedicated online backup service like Carbonite.

33. Windows System Updates
Check regularly for Windows system updates.
Such updates often increase overall system security and help resolve vulnerabilities.
Firewall
Ensure that your Windows Firewall is active, as this helps to protect from harmful incoming traffic. However, Windows Firewall should be supplemented with the (often superior) firewall of an anti-virus software.
Removable Devices
Removable devices like external hard drives and USB flash drives are a common way to spread viruses, care should be taken before mounting these devices or downloading and using any such related files.

34. Anti-virus
The most effective single step you can take is installing a dedicated anti-virus software suite.
A quality anti-virus software solution scan attachments and downloadable files for viruses.
It will perform constant checks and frequent scans of your system to ensure you are operating virus-free.
In cases where content is questionable, the software may flag the action or quarantine the data to provide an additional layer of awareness and protection.
The best anti-virus software also updates itself automatically in order to protect against the newest virus threats.

36. What To Look For In An Anti-virus Software
Does the anti-virus package come with a DOS boot disk and does it ask you to create an emergency repair disk during installation?
Does the anti-virus package offer option for scanning the boot record and a complete file scan immediately after pre-install scan?
Does the application check for file integrity?
How often can the user download virus signature updates?
Does the anti-virus software have the option of performing a heuristic analysis?
Is the anti-virus package capable of analyzing and disinfecting compressed archives such as .ZIP and .ARJ files, as well as disinfecting files within the archive?

37. Endnote
Even though the anti viruses and firewalls are meant to protect your PC from virus attacks, they are not completely efficient with their tasks. An anti-virus updates its database at a regular interval of 1 week minimum.
But with the vivid development of viruses all over, a new virus is being released in the world every next minute. Thus, your PC even with the most efficient anti-virus installed, is not completely safe from viruses.
Keep yourself updated with the latest information regarding the development of new viruses and their spreading medium for staying more cautious during your use of internet or getting files through various transfer mediums.