3 most dangerous computer viruses

1. ILOVEYOU a.k.a. Lovebug/Loveletter Virus

The ILOVEYOU virus was a computer virus that many consider to be the most damaging virus ever written. It spread itself by email in 2000 through an attachment in the message. Once opened, it loaded itself to the memory, infecting executable files. When a user received and opened the email containing the attachment “LOVE-LETTER-FOR-YOU.txt.vbs”, the computer became automatically infected. It then spread itself by infecting executable files, image files, as well as audio files like MP3s. After that, the virus sent itself to others by looking up the addresses contained in the MS Outlook contact list. The virus was written by a Filipino programmer who was still a college student at that time. He said the release of the virus was only “accidental.” This virus spread throughout the world in just a day, infecting computers of large corporations and governments, including the Pentagon in the United States. It caused billions of dollars in damages. The actual “damage” occurred during the removal of the infection from computers, as email servers and computer networks had to be shut down before the virus could be removed.

2. CIH a.k.a. Chernobyl Virus

This virus was considered one of the most dangerous and most destructive viruses ever because it had the ability to remain undetected in a computer’s memory, infecting every application that was run. First released in 1998, the CIH virus infected executable files of the operating systems Windows 95, 98, and ME. This virus also was accidentally distributed by a software vendor, contributing to the massive infection of computers. What made this virus dangerous was that it had a trigger date. Once that date was reached, it overwrote the files on the hard drive and completely destroyed its contents. It also had the ability to overwrite the BIOS of the computer to prevent it from booting up. This virus was also known as the Chernobyl virus because some variants were set to destroy data in computers that coincided with the nuclear power plant accident.

3. Melissa Virus

Released in 1999, the Melissa virus was another mass-mailing malware that was said to have infected up to 20 percent of computers worldwide. This included the networks of Microsoft, Intel, and other companies that relied on MS Outlook as their email client. Email servers around the world were forced to shut down in order to prevent the virus from spreading, as well as to remove the virus from their system. The virus came through email including an MS Word attachment. When opened, it emailed itself to the first 50 people in the MS Outlook contact list. It also overwrote the document files in the infected computer with quotes from the famous cartoon TV series “The Simpsons.”