Sometimes a computer virus goes way beyond a simple inconvenience and starts cyber-security history as one of the dangerous bugs of all time and we will tell you five of the worst viruses which can be so harmful to your PC.
You might not be shocked to learn that most of these viruses came as innocent-looking emails, and relied on users clicking through on unfamiliar attachments and links. In different words, it was social engineering, where hackers manage us to act a specific way to let them in.
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The first virus in the list is Melissa, from 1999, it uses a Word document attachment, it could fill up with porn sites and forward itself to more email addresses through a macro, a small bit of code worked to simplify repetitive tasks in Word.
If you question why Word sometimes locks down attachments you get over email, Melissa is part of the reason why. When it ran, it caused an estimated 80 million US$ in lost productivity and clean-up expenses.Despite this huge sum, a year later, it looks we still hadn’t learned our lesson. The ‘I Love You’ virus also relied on people’s interest in what was coming via email. Specifically, an attachment named love-letter-for-you.txt.
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That attachment was a small program that copied over private data from your local hard drive like Melissa, could mine email address books for new users to attack. I Love You ended up affecting roughly 45 million computers, and cost an estimated 10 billion dollars in damage.
In 2003, when SQL Slammer almost completely broke the internet and this time, there was no social engineering associated.Instead, the virus aimed data servers held by major companies, tricking them into giving it access to their systems, before sending itself out to other computers from its new owner.The snowballing result of more and more servers getting affected overloaded whole sections of the web, causing an expected 1.2 billion dollars in damage within the first 5 days.
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In 2007, Storm Worm used a link in an email instead of an attachment. A reminder, never click on links in your emails unless you’re certain they’re authentic.
Once the link was clicked, it could quietly install code and hook your computer up to a botnet, a shadowy, obscured network distributed over a number of internet-connected computers.Botnets can be utilized for everything from objective attacks on servers to running spam email campaigns. As they involve so many computers, security firms find them hard to stop.
Mebroot recognized from 2007 too, and it also selected computers to a botnet. The virus used drive-by-downloads to affect machines. Downloads that are automatically started as soon as a malicious website is started.
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Mebroot was able of taking control of computers deep inside their operating system, and as a result, it was very hard to stop. It could spy on pretty much everything you did in your browser; it only took a year to steal information linked to about 500,000 bank accounts.
We might be 9 years on from Mebroot, but there’s no place for complacency: viruses are only getting more difficult and trickier to catch. In fact, that sometimes they can hide for many years in systems before they’re uncovered.
And all the while we’re placing more and more of our lives online and ‘in the cloud’; we have greater amounts of private data at stake than ever before.
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There’s no way to ever be 100 % protected against a virus or a hack, but there are ways you can minimize the danger. Be cautious of links and attachments sent over email or prompt message, and keep all of your software like operating system, email client, browser, and antivirus program. So always up to date your system.