The Top 5 Lethal Viruses of All Times

Virus signifies anything viral and infectious. In clear terms, a computer virus is a software program that tends to replicate itself on execution and further engulfing or rather infecting other programs and so on. Getting a computer virus has happened to all of us in some fashion or the other, mostly it is just a mild inconvenience that we tend to suppress via cleanup and anti-viruses. Not to mention, it does work some way or the other. As a general practice, we also include computer worms and Trojans in the same genre as viruses.

Here, is a list down highlighting the worst of viruses which caused quite a lot of havoc and damage. These are not just any random viruses that we encounter, but amongst the worst witnessed that played a huge role in disrupting critical real life infrastructure along with billions of dollars of loss. Here we discuss the famous or the in-famous of all viruses:

1. ILOVEYOU

The ILOVEYOU as the name suggests (sarcastically) is considered one of the most virulent viruses of all times. It caused an estimated damage of $10 billion and was believed to have infected about 10% of world’s internet connected computers.

The virus was created by Filipino programmers, Reonel Ramones and Onel de Guzman. It used social engineering to get people to click on a TXT attachment, which in this case was a love confession, once clicked it will send itself to multiple people in the mailing list in addition to overwriting files with itself.

The two programmers where never charged due to their being no law against malwares which led to the enactment of the E-Commerce Law.

2. Code Red

Code Red, was the coined term for this virus because the two programmers were drinking code red mountain dew at the time of discovery. It was first surfaced in 2001 and was discovered by two employees of eEye Digital Security.

The main target for the worm was computer systems with Microsoft IIS web server installed and ultimately caused a buffer overflow problem in the system leaving very little trace on the hard disk and fully capable of running on memory. The virus proceeds by creating hundreds of copies of itself which ends up taking up a lot of system resources.

The most memorable symptom is the message it leaves behind on affected web pages, “Hacked By Chinese!”

3. Melissa

Named after an exotic dancer from Florida, Melissa, was developed in 1999 by David L. Smith who was eventually caught and agreed to cooperate with the government by serving a 20 Months sentence plus paid a fine of $5000.

The virus started as an infected word document posted up on the alt.sex usenet group. The doc claimed to be containing a list of passwords for pornographic websites. The curiosity of the user unleashed its payload. It would mail itself to top 50 people in your respective email address group leading to increased e-mail traffic, disrupting the e-mail services of government and corporations.

4. Sasser

Sasser was discovered in 2004 by a computer science student, Sven Jaschan, who was also the creator of Netsky worm. Jaschan was later tried as a minor and sentenced for 21 Months. The effects of this Windows worm were incredibly disruptive as it infected a huge number of computers along with critical infrastructure such as airlines, news agencies, public transportation, hospitals, public transport, etc.

It basically would slow down the system making it hard for it to rest without cutting out the power by taking advantage of a buffer overflow vulnerability in Local Security Authority Subsystem Service (LSASS) which is meant to control the security policy of local accounts. Overall, the damage was estimated to have cost $18 billion

5. Zeus

Zeus is Trojan horse which was identified in 2009, made to infect Windows computers to perform criminal tasks like man-in-the-browser keylogging and form grabbing. 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. As per estimations more than 1 million computers were infected, with 25% in the US

Most of the computers in this case were effected either through drive-by downloads or phishing scams. It involved people around the world to act as money mules to smuggle and transfer cash to the ringleaders in Eastern Europe. About $70 million were stolen and in possession of the ring. 100 people were arrested in connection of the operation.