Top 10 MOST DANGEROUS Computer Viruses Ever Created

What are computer viruses?

A computer virus is a malware made with a piece of code that when executed, will cause malicious damage to computer programs by replicating itself or adding pieces of code the other programs. Computer virus can be used to bypass security measures, steal data or change information, corrupt programs and cause many other types of damage.

Viruses come in several different formats. A true virus requires a host program to operate efficiently. Worms on the other hand, do not require a host program. This types of program breaks into computer networks and other programs by replication, which causes the installed operating system or programs to function incorrectly.


The ILOVEYOU VIRUS also known as the Love Pak or Love Bug is an example of a computer worm written in VBScript ("Microsoft Visual Basic Scripting Edition") VBScript allows Microsoft Windows to have the ability to administer and implement computer management tools that handle subroutines, errors and other advanced programming. This virus was said to have been created by Onel de Guzman from the Philippines. The charges were dropped due to a lack of evidence. During the time this virus was created, the time Philippines did not have any computer sabotage or computer espionage laws. This virus did an estimated 10 billion dollars in damage.

Code Red II

Code Red and Code Red II was a worm based infection that played on the vulnerability of Microsoft Windows 2000 and Windows NT. This virus worm would take avantage of the vulnerable program flaw that allowed the operating system's buffers to be saturated, forcing the system to overwrite adjacent memory. This virus actually attacked the White House's servers causing a crash.

A Klez worm


Slammer virus


Nimda worm