#33 Daily dose : The Top 5 computer virus


Getting a computer virus has happened to many users in some fashion or another. To most, it is simply a mild inconvenience, requiring a cleanup and then installing that antivirus program that you’ve been meaning to install but never got around to. But in other cases, it can be a complete disaster, with your computer turning into a very expensive brick which which no amount of antivirus can protect.

In this list, we will highlight some of the worst and notorious computer viruses that have caused a lot of damage in real life. And since people usually equate general malware like worms and trojan horses as viruses, we’re including them as well. These malware have caused tremendous harm, amounting to billions of dollars and disrupting critical real life infrastructure. Here are the 10 most famous and malicious computer viruses.

  1. ILOVEYOU

The ILOVEYOU virus is considered one of the most virulent computer  virus ever created and it’s not hard to see why. The virus managed to wreck havoc on computer systems all over the world, causing damages totaling in at an estimate of $10 billion. 10% of the world’s Internet-connected computers were believed to have been infected. It was so bad that governments and large corporations took their mailing system offline to prevent infection.
The virus was created by two Filipino programers, Reonel Ramones and Onel de Guzman. What it did was use social engineering to get people to click on the attachment; in this case, a love confession. The attachment was actually a script that poses as a TXT file, due to Windows at the time hiding the actual extension of the file. Once clicked, it will send itself to everyone in the user’s mailing list and proceed to overwrite files with itself, making the computer unbootable. The two were never charged, as there were no laws about malware. This led to the enactment of the E-Commerce Law to address the problem.
2. Code Red

Code Red first surfaced on 2001 and was discovered by two eEye Digital Security employees. It was named Code Red because the the pair were drinking Code Red Mountain Dew at the time of discovery. The worm targeted computers with Microsoft IIS web server installed, exploiting a buffer overflow problem in the system. It leaves very little trace on the hard disk as it is able to run entirely on memory, with a size of 3,569 bytes. Once infected, it will proceed to make a hundred copies of itself but due to a bug in the programming, it will duplicate even more and ends up eating a lot of the systems resources.
It will then launch a denial of service attack on several IP address, famous among them the website of the White House. It also allows backdoor access to the server, allowing for remote access to the machine. The most memorable symptom is the message it leaves behind on affected web pages, “Hacked By Chinese!”, which has become a meme itself. A patch was later released and it was estimate that it caused $2 billion in lost productivity. A total of 1-2 million servers were affected, which is amazing when you consider there were 6 million IIS servers at the time.
3. Melissa

Named after an exotic dancer from Florida, it was created by David L. Smith in 1999. It started as an infected Word document that was posted up on the alt.sex usenet group, claiming to be a list of passwords for pornographic sites. This got people curious and when it was downloaded and opened, it would trigger the macro inside and unleash its payload. The virus will mail itself to the top 50 people in the user’s email address book and this caused an increase of email traffic, disrupting the email services of governments and corporations. It also sometimes corrupted documents by inserting a Simpsons reference into them.
Smith was eventually caught when they traced the Word document to him. The file was uploaded using a stolen AOL account and with their help, law enforcement was able to arrest him less than a week since the outbreak began. He cooperated with the FBI in capturing other virus creators, famous among them the creator of the Anna Kournikova virus. For his cooperation, he served only 20 months and paid a fine of $5000 of his 10 year sentence. The virus reportedly caused $80 million in damages.
4. Sasser

A Windows worm first discovered in 2004, it was created by computer science student Sven Jaschan, who also created the Netsky worm. While the payload itself may be seen as simply annoying (it slows down and crashes the computer, while making it hard to reset without cutting the power), the effects were incredibly disruptive, with millions of computers being infected, and important, critical infrastructure affected. The worm took advantage of a buffer overflow vulnerability in Local Security Authority Subsystem Service (LSASS), which controls the security policy of local accounts causing crashes to the computer. It will also use the system resources to propagate itself to other machines through the Internet and infect others automatically.
The effects of the virus were widespread as while the exploit was already patched, many computers haven’t updated. This led to more than a million infections, taking out critical infrastructures, such as airlines, news agencies, public transportation, hospitals, public transport, etc. Overall, the damage was estimated to have cost $18 billion. Jaschen was tried as a minor and received a 21 month suspended sentence.
5. Zeus

Zeus is a Trojan horse made to infect Windows computers so that it will perform various criminal tasks. The most common of these tasks are usually man-in-the-browser keylogging and form grabbing. The majority of computers were infected either through drive-by downloads or phishing scams. First identified in 2009, it managed to compromise thousands of FTP accounts and computers from large multinational corporations and banks such as Amazon, Oracle, Bank of America, Cisco, etc. Controllers of the Zeus botnet used it to steal the login credentials of social network, email and banking accounts.

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