Computer virus

COMPUTER
VIRUSES
WEAPONS OF MASS DISRUPTION
shubhamindrawat@gmail.com www.linkedin.com/in/shubhamindrawat

INDEX
1. INTRODUCTION
2. HISTORY
3. TYPES OF VIRUSES
1. BOOT VIRUS
2. PROGRAM VIRUS
3. MACRO VIRUS
4. FUNCTIONS
5. SOURCE OF VIRUSES
6. PREVENTION

INTRODUCTION
• VIRUS IS AN ABBREVIATED FORM OF VITAL INFORMATION RESOURCE UNDER SEIZE
• A COMPUTER VIRUS IS A TYPE OF MALICIOUS SOFTWARE PROGRAM (“MALWARE")
THAT, WHEN EXECUTED, REPLICATES BY REPRODUCING ITSELF (COPYING ITS OWN
SOURCE CODE) OR INFECTING OTHER COMPUTER PROGRAMS BY MODIFYING THEM.
• INFECTING COMPUTER PROGRAMS CAN INCLUDE DATA FILES OR THE "BOOT"
SECTOR OF THE HARD DRIVE.
• WHEN THIS REPLICATION SUCCEEDS, THE AFFECTED AREAS ARE THEN SAID TO BE
"INFECTED" WITH A COMPUTER VIRUS.

HISTORY
• THE FIRST EVER COMPUTER VIRUS WAS DEVELOPED IN 1986 BY TWO PAKISTANI
BROTHERS (AMJAD FAROOQ ALVI AND BASIT FAROOQ ALVI) IN LAHORE,
PAKISTAN.
• THAT VIRUS WAS NAMED "BRAIN“ AND WAS DESIGNED WITH THE INTENTION OF
DETERMINING THE PIRACY OF A SOFTWARE WRITTEN BY THEM.

WORLD’S WORST ATTACKS
• LOVE LETTER
• LOVELETTER IS THE VIRUS EVERYONE LEARNED TO
HATE IN 2000. THE INFECTION AFFECTED MILLIONS
OF COMPUTERS AND CAUSED MORE DAMAGE THAN
ANY OTHER COMPUTER VIRUS TO DATE. THE MAIL
INCLUDED AN EXECUTABLE FILE ATTACHMENT WITH
THE E-MAIL SUBJECT LINE, "ILOVEYOU“
• THE WORM HAD THE ABILITY TO OVERWRITE SEVERAL
TYPES OF FILES, INCLUDING .GIF AND .JPG FILES. IT
MODIFIED THE INTERNET EXPLORER START PAGE AND
CHANGED REGISTRY KEYS. IT ALSO MOVED OTHER
FILES AND HID MP3 FILES ON AFFECTED SYSTEMS.

• MELISSA
• THE MELISSA VIRUS SWAMPED CORPORATE NETWORKS WITH A TIDAL WAVE OF E-
MAIL MESSAGES IN MARCH 1999. THE VIRUS WAS SENT TO THE FIRST 50 NAMES IN
THE USER'S ADDRESS BOOK.
• THE E-MAIL FOOLED MANY RECIPIENTS BECAUSE IT BORE THE NAME OF SOMEONE
THE RECIPIENT KNEW AND REFERRED TO A DOCUMENT THEY HAD ALLEGEDLY
REQUESTED.

• NIMDA
• NIMDA (ALSO KNOWN AS THE CONCEPT
VIRUS) APPEARED IN SEPTEMBER 2001,
ATTACKING TENS OF THOUSANDS OF
SERVERS AND HUNDREDS OF THOUSANDS OF
PCS. THE WORM MODIFIED WEB DOCUMENTS
AND EXECUTABLE FILES, THEN CREATED
NUMEROUS COPIES OF ITSELF.
• NIMDA SOON INSPIRED A CROWD OF
IMITATORS THAT FOLLOWED THE SAME
PATTERN.

• ANNA KOURNIKOVA WORM
• THE ANNA KOURNIKOVA WORM, APPEARING IN
FEBRUARY 2001, DIDN'T CAUSE DATA LOSS, IT
DID CAUSE EMBARRASSMENT AND DISRUPTION
FOR MANY PERSONAL AND BUSINESS USERS.
• THE WORM SHOWED UP IN MICROSOFT
OUTLOOK USERS' E-MAIL IN-BOXES WITH AN
ATTACHMENT MOST WORM CREATORS HAVE
NEVER BEEN IDENTIFIED, BUT A 21-YEAR-OLD
DUTCHMAN, JAN DE WIT, ADMITTED TO
UNLEASHING THIS WORM.

MAJOR CATEGORIES OF VIRUSES

BOOT VIRUS
• A BOOT SECTOR VIRUS IS A TYPE OF VIRUS THAT INFECTS THE BOOT SECTOR OF
FLOPPY DISKS OR THE MASTER BOOT RECORD (MBR) OF HARD DISKS (SOME
INFECT THE BOOT SECTOR OF THE HARD DISK INSTEAD OF THE MBR).
• GENERALLY THESE ARE THE MOST DANGEROUS ONES, AS THEY INFECT THE
BOOT FILES OF THE SYSTEM OR HARD DISKS.

PROGRAM VIRUS
• THESE VIRUSES INFECT PROGRAM FILES, WHICH HAVE EXTENSIONS LIKE .COM,
.EXE, .BAT, .SYS, .DLL, .OVL, OR .SCR.
• PROGRAM FILES ARE ATTRACTIVE TARGETS FOR COMPUTER VIRUS BECAUSE
THEY ARE WIDELY USED AND HAVE RELATIVITY, SIMPLE FORMATS TO WHICH
VIRUSES CAN ATTACH THEMSELVES.

MACRO VIRUS
• A MACRO VIRUS IS A COMPUTER VIRUS THAT "INFECTS" A MICROSOFT WORD OR
SIMILAR APPLICATION AND CAUSES A SEQUENCE OF ACTIONS TO BE PERFORMED
AUTOMATICALLY WHEN THE APPLICATION IS STARTED OR SOMETHING ELSE
TRIGGERS IT.
• MACRO VIRUSES TENDS TO BE SURPRISING BUT RELATIVELY HARMLESS.
• A TYPICAL EFFECT IS THE UNDESIRED INSERTION OF SOME COMIC TEXT AT
CERTAIN POINTS WHEN WRITING A LINE. A MACRO VIRUS IS OFTEN SPREAD AS
AN E-MAIL VIRUS.

WORKING OF COMPUTER VIRUS
• TECHNICALLY A VIRUS IS A PROGRAM OR CODE THAT ATTACHES ITSELF TO A
LEGITIMATE, EXECUTABLE PIECE OF SOFTWARE, AND THEN REPRODUCES ITSELF
WHEN THAT PROGRAM IS RUN.
• VIRUSES SPREAD BY REPRODUCING AND INSERTING THEMSELVES INTO PROGRAMS,
DOCUMENTS, OR E-MAIL ATTACHMENTS. THEY CAN BE TRANSMITTED THROUGH E-
MAILS OR DOWNLOADED FILES AND THEY CAN BE PRESENT ON CDS, DVDS, USB-
DRIVES AND ANY OTHER SORT OF DIGITAL MEDIA.
• A VIRUS NORMALLY REQUIRES AN ACTION TO INFECT A VICTIM. FOR INSTANCE, THE
MALICIOUS PROGRAMS INSIDE E-MAIL ATTACHMENTS USUALLY ONLY STRIKE IF YOU
OPEN THEM. THE EFFECT OF A VIRUS CAN BE ANYTHING FROM A SIMPLE PRANK
THAT POPS UP MESSAGES TO THE COMPLETE DESTRUCTION OF PROGRAMS AND
DATA.

SOURCE OF VIRUSES
• DOWNLOADABLE PROGRAMS
• CRACKED SOFTWARE
• EMAIL ATTACHMENTS
• INTERNET
• BOOTING FROM CD/PEN DRIVES
• MALICIOUS WEBSITES

PREVENTION
• INSTALLING ANTI-VIRUS SOFTWARES
• UPDATE ANTI-VIRUS SOFTWARE REGULARLY
• UPDATING YOUR OPERATING SYSTEM
• SECURING YOUR NETWORK
• KEEP PERSONAL INFORMATION SAFE
• AVOID USING OPEN WIFI
• BACKUP YOUR FILES
• THINK BEFORE YOU CLICK
• USE MULTIPLE STRONG PASSWORDS

BIBLIOGRAPHY
• https://google.co.in
• https://en.wikipedia.org/wiki/Virus
• https://www.slideshare.net/shohrabkhan/computer-virus-37102804
• http://files-recovery.blogspot.in/2010/06/20-common-types-of-computer-
viruses-and.html
• https://priceonomics.com/who-invented-the-computer-virus/
• http://www.bullguard.com/bullguard-security-center/pc-security/computer-
threats/how-does-a-virus-work.aspx
• https://redshift.autodesk.com/10-tips-on-how-to-prevent-malware-from-
infecting-your-computer/

THANK
YOU
PREPARED BY:-
SHUBHAM INDRAWAT

Computer virus

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