Posted on June 3rd, 2010Computer Viruses & Worms! These are the most dreaded words which strike fears into a users heart! Definitely harmful for the home PCs, but the financial damage caused is minimal when it compared with the destruction that is caused to an organization or a company. The data stored in disks have become really valuable such that even the minute loss of it can cost you millions of dollars.
These are the few computer viruses from the past that are classified as the worst ever in the industry.
1.) Morris
Morris, named after Robert Tappan Morris, created the virus in 1988. It was one of the first viruses reported in the world. Actually it was coded to find the size of the Internet. The error that he made in the code made the harmless worm into a deadly one which caused a loss between $10 million – $100 million US dollars. Morris, presently the Professor of Cornell University, was fined for his adventurous creation.
2.) Melissa
Melissa, created and named (after a bar dancer) by David L Smith, was reported in 1999. The virus was attached along with emails which had a message: “Here is that document you asked for, don’t show it to anybody else.” As soon as it got activated, it sends the same to the top 50 people in the contacts list. It caused a heavy damage in the industry and it lead to the shutting down of email gateways of companies like Intel Corp., Alcatel Lucent, Microsoft .etc
3.) Love letter
The virus that broke the heart of (and robbed people of) millions! It was an email with a subject “I LOVE YOU” which had an attachment LOVE-LETTER-FOR-YOU.TXT.vbs. The users didn’t know that it was a Visual Basic Script because the extension was hidden. The virus copied itself to all the addresses in the Windows address book with the user’s sender address. It also brought malicious changes to the user’s system. The most expensive love letter in the world which caused a damage of $ 10 billion.
4.) The Klez Virus
The Klez virus was also capable of self replication and spoofing like the other worms. In addition to that, it disabled the anti-virus software and made the system vulnerable to other malicious attacks. The other advantage of the worm was that it could act as a normal virus, worm or a Trojan depending on its versions. But just because it existed in the past doesn’t mean it’s not coming back. Hackers are working on this little menace to make it more malicious, so don’t say we didn’t warn you.
5.) Code Red
The Code Red worm, released on 13th July, 2001, attacked Microsoft’s IIS web servers
The worm sneaked through the server through a patch in the indexing software with IIS. It used the buffer overflow technique (a long string of repeated character ‘N’ was used to overflow a buffer). A fix was found in a month’s time which limited the damage to $2.5 billion! A similar worm was released 2 weeks after Code Red and they named it as Code Red II.
6.) Nimda
The worm, also a file infector, spread through out the world in 22 minutes. The reason why Nimda was more effective than others was because it used different methods for propagation. It not only used emails but also open network shares, backdoor left by other viruses etc. Nimda spelled backwards is “Admin”! Damage caused by Nimda : $ 635 million!
7.) SQL Slammer
Don’t be fooled by the name, this slammer does not use any SQL commands but on the contrary, it actually exploits the vulnerability in the Microsoft SQL servers and uses the buffer overflow bug to slow down the servers. The worst part of it is that it causes DoS attacks (Denial of Service) and also slows down the entire Internet. Up to date, around 200,000 systems have been affected by this worm.
8.) MS Blaster
Blaster came to existence in August, 2003 and it began to crack the Windows Operating Systems. Also, it targeted the windowsupdate.com site with DoS attacks which resulted in multiple restarts in machines running Windows NT, XP (64 bit) and Windows 2003. Companies and organizations like the Federal Reserve Bank of Atlanta, BMW AG, Philadelphia’s City Hall, and thousands of home and corporate users were blasted by the Blaster!
9.) MyDoom
MyDoom, also known as W32.MyDoom@mm, Novarg, Mimail.R and Shimgapi, attacks systems with Microsoft Windows. The fastest spreading email worm ever, appears with a text message, “andy; I’m just doing my job, nothing personal, sorry,”. There are 2 versions of MyDoom worms: MyDoom.A and MyDoom.B. Both the versions attack through backdoor. Additional feature of MyDoom.B to block Microsoft website and to block HTTP access to other anti-virus websites make it extremely dangerous worm.
10.) Witty
Witty worm was released in March, 2004. It attacks firewall and other security products of Internet Security Systems (ISS) – now IBM Internet Security System. It got the name witty because of the message “(^.^) insert witty message here (^.^)” which was attached with the worm. The cute little ‘Witty’ worm infected 12000 computers in 30 minutes and generated 90 Gbps of UDP traffic.
Shame you gave no mention to Stuxnet. I wouldn’t say it was the most harmful of computer viruses to the “general public” but I am sure it cause insurmountable damages to Iran’s nuclear facilities.