10 worst online threats ever   |  November 24, 2009  

Celebrate the anniversary of the Internet with the

10 worst online threats ever

By Peter Wolchak

Sept. 2 was the 40th anniversary of the Internet. To commemorate, Symantec compiled a list of the 10 worst online threats ever.

1. I Love You (2000) Everyone wanted to open an e-mail with “I Love You” in the subject line. Clever, those scammers, eh? By May 2000, 50 million infections by this worm had been reported. The Pentagon, the CIA and the British Parliament all had to shut down their e-mail systems in order to purge the threat.

2. Conficker (2009) The Conficker worm created a secure worldwide infrastructure for cybercrime, as it allows its creators to install software on infected machines. The goal is likely the creation of a botnet that will be rented out to criminals.

3. Melissa (1999) Melissa was an exotic dancer and David L. Smith was obsessed with her, and also with writing viruses. The virus he released on March 26, 1999 kicked off a period of high-profile threats that rocked the Internet between 1999 and 2005.

4. Slammer (2003) This fast-moving worm managed to temporarily bring much of the Internet to its knees in January 2003. It was so aggressive some countries believed it was an organized attack against them.

5. Nimda (2001) A mass-mailing worm that used multiple methods to spread itself, within 22 minutes Nimda became the Internet’s most widespread worm.

6. Code Red (2001) Sites hit by the Code Red worm were defaced by the phrase “Hacked By Chinese!” Infected hosts reached 359,000.

7. Blaster (2003) This worm launched a denial-of-service attack on www.windowsupdate.com and included the message “billy gates why do you make this possible? Stop making money and fix your software!!”

8. Sasser (2004) This nasty worm spread by exploiting a vulnerable network port, allowing it to move without user intervention. Sasser wreaked havoc on everything from The British Coast Guard to Delta Airlines.

9. Storm (2007) Microsoft was again the target. Storm’s payload performed a denial-of-service attack on www.microsoft.com. Symantec observed an infected machine sending almost 1,800 e-mails in a five-minute period.

10. Morris (1988) Robert Morris claimed he wrote this worm to gauge the size of the Internet. Unfortunately, an error caused it to infect computers multiple times, creating a denial of service.