Computer Virus
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A computer virus is a self-replicating program that can infect computers without the owner's consent, with notable examples including the Creeper virus from the 1970s and the Melissa and I Love You viruses from the late 1990s. Viruses can take various forms, such as trojan horses and worms, and exhibit behaviors like altering files or slowing down system performance. Prevention methods include using antivirus software, being cautious with emails and attachments, and regularly updating protective software.
Computer Virus
- 2. What is a Computer Virus? •A computer virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the owner. •One of the first detected virus was the Creeper virus in the early 70’s •Before computer networks became widespread, most viruses spread on removable media, particularly floppy disk.
- 3. What is a Computer Virus? •A computer virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the owner. •One of the first detected virus was the Creeper virus in the early 70’s •Before computer networks became widespread, most viruses spread on removable media, particularly floppy disk.
- 4. Basic Computer Viruses •Trojan Horses • appears as interesting program file but when installed it allows intruders to access and read your files •Worms • virus that copies and multiplies itself by using computer networks and security flaws •E-mail Viruses • use e-mail messages to spread which allow it to automatically forward itself to thousands of people
- 5. Types of Viruses • Boot Sector Virus • Infects the boot or MBR of diskettes and hard drives through the sharing of infected disks and pirated software applications • Once your hard drive is infected all diskettes that you use in your computer will be infected • Program Virus • Becomes active when the program file (usually with extensions .BIN, .COM, .EXE, .OVL, .DRV) carrying the virus is opened • It then makes copies of itself and will infect other programs on the computer • Multipartite Virus • Hybrid of a Boot Sector and Program viruses • It infects program files and when the infected program is active it will affect the boot record
- 6. Types of Viruses • Stealth Virus • Disguises itself to prevent from being detected by antivirus software • It alters its file size or conceals itself in memory • Polymorphic Virus • Act like a chameleon, changing its virus signature (binary pattern) every time it multiples and infects a new file • Macro Virus • Programmed as a macro embedded in a document, usually found in Microsoft Word and Excel • Once it gets in to your computer, every document you produce will become infected • Relatively new type of virus and may slip by your antivirus software if you don't have the most recent version installed
- 7. Signs Your Computer is Infected • Functions slower than normal • Responds slowly and freezes often • Restarts itself often • See uncommon error messages, distorted menus, and dialog boxes • Notice applications fail to work correctly • Fail to print correctly
- 9. • First half of the 70'Late 60,s, early 70,s- "Rabbits" cloned themselves occupied system resources, slowing down the productivity. • -"The Creeper" capable of entering a network by itself and transferring a copy of itself to the system. • Early 80,s-Increasing number of programs written by individuals not by software companies. Programs caused miner viruses called "Trojan horses". • 1986'Brain virus' - by Amjad and Basit Farooq Alvi. - spread through floppy disks, - infected boot records and not computer hard drives • Lahore, Pakistani Brain, Brain-A and UIUC virus -took over free space on the floppy disk and hid from detection ”disguised itself by displaying the uninfected boot sector on the disk.” • 1987-Lehigh virus - the first memory resident file infector that attacked executable files and took control when a file was opened • The Jerusalem Virus -had bugs that re-infected programs that were already infected
- 10. 1988: Robert Morris made a worm that invaded ARPANET computers - disabled 6,000 computers on the network by overflowing their memory banks with copies of itself 1991: Norton Anti-Virus software 1999: "Melissa" virus -infected thousands of computers very fast by sending copies of itself to 50 names in the address book on Outlook e-mail - Led to an estimated $80 million in damage and record sales of anti-virus products. 2000: "I Love You" virus -was sent by email and infected 10 % of computers in only one day -created by a young Filipino computer student who did not get punished because then the Philippines had no laws against hacking which led to the European Union's global Cybercrime Treaty. 2001: "Nimda" virus (days after 9/11) -had 5 ways of infecting systems
- 11. • 2004 • MyDoom spreads through emails and file-sharing software faster than any previous virus or worm. • Allows hackers to access the hard drive of the infected computer. • An estimated one million computers running Windows are affected by the fast-spreading Sasser computer worm. • The worm does not cause irreparable harm to computers or data, but it does slow computers and cause some to quit or reboot without explanation. • 2006 • Discovery of the first-ever malware trojan horse for Mac OS X • 2008 • Torpig is a Trojan horse which affects Windows, turning off anti-virus applications. • It allows others to access the computer, modifies data, steals confidential information and installs malware on the victim's computer. • 2009 • Conficker infects anywhere from 9 to 15 million Microsoft server systems. • French air force, Royal Navy warships and submarines, Sheffield Hospital network, UK Ministry of Defence, German Bundeswehr and Norwegian Police were all affected.
- 12. Total Number of Viruses by year January 1985 1 January 1985 1 January 1987 3 January 1989 6 January 1990 142 January 1991 357 January 1992 1,161 January 1993 2,482 January 1994 3,687 January 1995 5,626 January 1996 7,764 January 1997 11,037 January 1998 16,726 January 1999 40,850 January 2000 44,000 January 2001 48,000 January 2002 55,000 January 2003 62,000
- 13. Melissa • Another virus that fired up the media was Melissa, a Word macro virus. • When people received the host Word document via email and opened it, the virus sent a copy of itself to the first 50 people in the victim's address book. • Named after a topless dancer in Florida, the Melissa virus crashed the email servers of corporations and governments in different spots around the world. • The Computer Emergency Response Team, set up after Robert Morris mucked up the Internet with his worm in 1988, estimated that the virus hit 100,000 computers in its first weekend. • David L. Smith posted the infected file to an alt.sex usenet group using a stolen AOL account. Initially he entered a plea of innocence, but after being confronted with a maximum sentence of 40 years in prison, he eventually pled guilty and received a much-reduced sentence.
- 14. Love You, Love Bug • By almost any measure, the so-called Love Bug was the most damaging and costly virus ever. I don't know who comes up with these whack figures, but according to Reuters the bug cost the world $15 billion in lost productivity. • The Love Bug spread far faster than Melissa. Unlike Melissa, it would mail itself to everyone in your Outlook address book -- most of whom would probably be delighted to read about how you love them -- not just the first fifty. Moreover, it would gobble up certain media files stored on your hard drive.
- 15. Did you know? • One German newspaper tragically lost 2,000 pictures from its archive. • The perpetrator turned out to be a 23-year-old Filipino computer science student who more or less plagiarized all of his code. • The lack of laws in the Philippines covering computer crimes, he pretty much got away with his crime.
- 16. Prevention • Upload and use antivirus software • Be aware of the e-mails and attachments you open • Check for updates on antivirus software regularly • Make sure antivirus software is installed correctly
- 19. Thank You