TOP 11 VIRUSES OF ALL TIME

TOP 11 VIRUSES OF ALL TIME:

1.The Elk Cloner virus was written for Apple DOS 3.3 and spread via  

floppy disks; it displayed a short poem and was activated on its 50th use. The  

Elk Cloner virus was the first PC virus. 

2. The Brain virus was the first worldwide virus to also spread by floppy  

disks, and the two brothers in Pakistan who wrote the virus did not intend for  

it to be a destructive virus, yet despite their intentions, it materialized into one. 

3.The Melissa virus was based on a Microsoft Word Macro and was designed  

to infect e-mail messages by sending infected word documents to the first 50  

people in a user’s outlook list. The Melissa virus was reported to cause more  

than $50 million in damages to other computer users and businesses. 

4. The I Love You virus infected millions of computers in a single day sim- 

ply because the attachment stated “I Love You” and people’s curiosity caused  

them to open the infected attachment, which, when opened, would copy  

itself in different files on the user’s hard drive and also download a file that  

stole passwords from the victim. 

5. The Code Red virus was directed to attack the U.S. White House as a  

distributed denial-of-service attack, but it was stopped before it could effect  

the attack. However, this virus did infect thousands of computers and caused  

over $1 billion dollars in damages. A second version, Code Red II, attacked  

Windows 2000 and Windows NT systems. 

6. The Nimda virus was one of the fastest propagating viruses to enter the  

Internet, and its targets were Internet servers; it really worked as a worm and  

caused significant damage to many users. 

7. The Slammer virus in 2003 was a Web server virus that also roamed  

through the Internet at incredible speed. Many corporations in both the  

financial services and airline industries suffered significant losses estimated  

in the range of several billion dollars. 

8. The My Doom virus used a denial-of-service attack script and sent search  

engine requests for e-mail addresses, causing companies such as Google to  

receive millions of requests and severely slow down services and, in some  

cases, to close down companies. 

9. Worms do not change other programs, but a worm is a computer pro- 

gram that has the ability to replicate itself from computer to computer and to  

cross over to network connections. It is important to stress that while worms  

do not change other programs, they may carry other code that does change  

programs, such as a true virus.14 

10. In 2007, the “Storm” worm used social media approaches to fool com- 

puter users into situations where they loaded botnets into their computers,  

and Bruce Schneier reported that millions of computers were infected by this  

worm, which carried virus code as well. 

11. A Trojan horse is a program that masquerades as a legitimate applica- 

tion while also performing a covert function. Trojan horse programs do not  

propagate on their own, so they rely on users to accept the executables from Historical Reference Points in the Computer Industry 11 

untrusted sources. Consequently, this becomes a major social engineering  

problem