What Is The Most Damaging Virus Attack?

BY Ray Stevens / ON May 04, 2021

Computer security is paramount, with all aspects of a computer system, including the user, needing to be protected, wary and ready to spot suspicious signs of a potential virus attack.

The idea of a computer virus, as in a computer program that can replicate itself very quickly has existed for over 70 years, and the first article on the subject was written by John von Neumann in 1966.

The first virus ever made, Creeper, is 50 years old this year and would lay the foundations for one of the most devastating computer security attacks in recent history, one that intensified the need for phishing simulation and the importance of user awareness of potentially damaging viruses.

This is the story of the computer worm MyDoom, to this day the fastest spreading and most damaging virus attack ever.

What Is A Computer Worm?

To understand how devastating MyDoom and viruses like it were, we need to understand how they work and the history of viruses like it.

A virus is a piece of self-replicating computer code that modifies (or infects) other programs and adds its own code, meaning that other programs in the system can activate or reactivate the virus’ effects.

A computer worm is a standalone computer program that replicates and spreads across a network, taking advantage of weaknesses in security systems to spread and copy itself.

The first two worms ever made, Creeper and Reaper were harmless, the former writing a message on networked output machines and the latter deleting Creeper.

This self-contained type of virus would become the weapon of choice for some of the most damaging cyberattacks ever.

The Mydoom Attack

After the unintentional damage caused by the Morris Worm in 1988 and the huge damage caused by ILOVEYOU in 2000, it was clear that computer worms that could take advantage of email systems would be the fastest way to make a virus spread.

Unlike those two, which were written out of curiosity and out of desperation respectively, MyDoom was written as a way to send spam emails to people through infected computers.

Unfortunately, as the author of the virus is unknown we will not know for sure what the reason for its creation was.

It was sent as an email attachment, usually with a message title that attempted to replicate an email sending error, such as “Mail Transaction Failed” or “Mail Delivery System”, and the body of the email says that the message has been sent as an attachment.

The executable file looks like a text file, catching millions of people off guard.

If the executable file is clicked on it rapidly installs a system to allow hackers to break into the system as well as a keylogger to track passwords. Next, it starts scanning local files and Outlook’s address books to find email addresses, which it will use to send and spread the virus further.

Within a few hours of its first infection on 26th January 2004, the virus had slowed the entire internet by 10 per cent and doubled the amount of time web pages took to load.

The software also targeted both Microsoft and a company that had claimed to own the UNIX operating system, which initially made people believe that it was an act of activism by fans of the open-source system Linux.

This turned out not to be the case, but regardless, no virus has done as much damage since MyDoom.