Computers viruses, worms, ransomware, etc. are kinds of malicious software that no user should take lightly. On several occasions, we have touched upon security steps that each user should take in order to protect its identity and data. Sadly sometimes even when all precautions are taken some malware can still slip through and wreak havoc. Today we are looking at some of the worst or the best, depending on your view that has indeed wreaked plenty of havoc.
10 worst computer viruses in historyIn the list of the 10 most famous computer viruses below, we show the costs, dates, reach, and other key facts. First a note about terms: we use the words “virus” and “worm” interchangeably because most readers search for them that way. But there’s a subtle difference that we explain after the list.
The worst computer virus outbreak in history, Mydoom caused estimated damage of $38 billion in 2004, but its inflation-adjusted cost is actually $52.2 billion. Also known as Novarg, this malware is technically a “worm,” spread by mass emailing. At one point, the Mydoom virus was responsible for 25% of all emails sent.
Mydoom scraped addresses from infected machines, then sent copies of itself to those addresses. It also roped those infected machines into a web of computers called a botnet that performed distributed denial of service (DDoS) attacks. These attacks were intended to shut down a target website or server.
Mydoom is still around today, generating 1% of all phishing emails. That’s no small feat considering the 3.4 billion phishing emails sent each day. By that figure, Mydoom has taken on a life of its own, infecting enough poorly-protected machines to send 1.2 billion copies of itself per year, 16 years after its creation.
Though a $250,000 reward was offered, the developer of this dangerous computer worm was never caught.
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The 2003 Sobig computer virus is actually another worm. It is second only to the Mydoom virus in its scope. The $30 billion figure is a worldwide total, including Canada, the U.K., the U.S., mainland Europe, and Asia. Several versions of the worm were released in quick succession, named Sobig.A through Sobig.F, with Sobig.F being the most damaging.
This cybercriminal program masqueraded as legitimate computer software attached to emails. It disrupted ticketing at Air Canada and interfered with countless other businesses. Despite its widespread damage, the creator of the successful bug was never caught.
Klez is a close third on the list of the worst computer viruses ever created. With nearly $20 billion in estimated damages, it infected about 7.2% of all computers in 2001, or 7 million PCs. The Klez worm sent fake emails, spoofed recognized senders and, among other things, attempted to deactivate other viruses.
As with other viruses and worms, Klez was released in several variants. It infected files, copied itself, and spread throughout each victim’s network. It hung around for years, with each version more destructive than the last.
Windows has come a long way since most of the computer viruses on this list hit the web. Thankfully, built-in protection with Microsoft Defender is always on the watch.
The year 2000’s ILOVEYOU virus worked by sending a bogus “love letter” that looked like a harmless text file. Like Mydoom, this attacker sent copies of itself to every email address in the infected machine’s contact list. Shortly after its May 4 release, it had spread to more than 10 million PCs.
The virus was created by a college student in the Philippines named Onel de Guzman. Lacking funds, he wrote the virus to steal passwords so he could log into online services he wanted to use for free. He reportedly had no idea how far his creation would spread. This virus is also known as Loveletter.
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The 2017 WannaCry computer virus is ransomware, a virus that takes over your computer (or cloud files) and holds them hostage. The WannaCry ransomware ripped through computers in 150 countries, causing massive productivity losses as businesses, hospitals, and government organizations that didn’t pay were forced to rebuild systems from scratch.
The malware raged like wildfire through 200,000 computers worldwide. It stopped when a 22-year-old security researcher in the U.K. found a way to turn it off. Computers with out-of-date operating systems were hit especially hard. That’s why security experts always recommend updating your systems frequently.
In September 2020, one of the potentially largest computer virus attacks in medical history hit Universal Health Services. The U.S. hospital chain, which has more than 400 locations, was reportedly struck by damaging ransomware. The attack forced the cancellation of surgeries and made healthcare workers switch to paper records.
The Zeus computer virus is an online theft tool that hit the web in 2007. A whitepaper by Unisys three years later estimated that it was behind 44% of all banking malware attacks. By then, it had breached 88% of all Fortune 500 companies, 2,500 organizations total, and 76,000 computers in 196 countries.
The Zeus botnet was a group of programs that worked together to take over machines for a remote “bot master.” It originated in Eastern Europe and was used to transfer money to secret bank accounts. More than 100 members of the crime ring behind the virus, mostly in the U.S., were arrested in 2010. It’s not as prominent today, but some of the virus’ source code lives on in newer botnet viruses and worms.
Zeus caused documented damage of $100 million. But the real cost in terms of lost productivity, removal, and undocumented theft is undoubtedly much higher. A $3 billion estimate, adjusted for inflation, puts this virus at a cost of $3.7 billion in today’s dollars.
First observed in 2001, the Code Red computer virus was yet another worm that penetrated 975,000 hosts. It displayed the words “Hacked by Chinese!” across infected web pages, and it ran entirely in each machine’s memory. In most cases it left no trace in hard drives or other storage.
Financial costs are pegged at $2.4 billion. The virus attacked websites of infected computers and delivered a distributed denial of service (DDoS) attack on the U.S. White House’s website, www.whitehouse.gov. In fact, the White House had to change its IP address to defend against Cod Red.
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The SQL Slammer worm cost an estimated $750 million across 200,000 computer users in 2003. This computer virus randomly selected IP addresses, exploiting vulnerabilities and sending itself on to other machines. It used these victim machines to launch a DDoS attack on several internet hosts, significantly slowing internet traffic.
The Slammer worm hit banks in the U.S. and Canada especially hard, taking ATMs offline in many locations. Customers of Toronto’s Imperial Bank of Commerce found themselves unable to access funds. The attack reared its ugly head again in 2016, launching from IP addresses in Ukraine, China, and Mexico.
Thankfully, ransomware attacks like the 2013 CryptoLocker virus have dipped since their 2017 peak. This malware attacked upwards of 250,000 machines by encrypting their files. It displayed a red ransom note informing users that “your important files encryption produced on this computer.” A payment window accompanied the note.
The virus’ creators used a worm called the Gameover Zeus botnet to make and send copies of the CryptoLocker virus. According to a report by security firm Sophos, the average ransomware attack costs a business $133,000. If we estimate that CryptoLocker hit 5,000 companies, that would put its total cost at $665 million.
Where will cybersecurity go next? See our guide: The Future of Cybersecurity
The Sasser worm was written by a 17-year-old German computer science student named Sven Jaschan. He was arrested at the age of 18 in 2004 after a $250,000 bounty was posted for the computer virus’ creator. A friend of Jaschan’s tipped authorities that the youth had penned not only the Sasser worm but also the damaging Netsky.AC attack.
Jaschan was given a suspended sentence after it was found he was a minor when he wrote the malware. The Sasser worm crashed millions of PCs, and though some reports put damages at $18 billion, the relatively low infection rate suggests a more likely cost of $500 million.
Other notable viruses
The top 10 worst computer viruses above are just the ugly tip of a gargantuan digital iceberg. With a million new malware programs popping up every 3 years, we may miss the forest for a few outstanding trees. Here are just a few more viruses that have wreaked havoc over the years:
Mimail: This worm tried to harvest data from infected machines to launch a string of DDoS attacks, but was relatively easy to remove.
Yaha: Yet another worm with several variants, thought to be the result of a cyber-war between Pakistan and India.
Swen: Written in C++, the Swen computer worm disguised itself to look like a 2003 OS update. Its financial cost has been pegged at $10.4 billion, but not reliably.
Storm Worm: This worm showed up in 2007 and attacked millions of computers with an email about approaching bad weather.
Tanatos/Bugbear: A 2002 keylogger virus that targeted financial institutions and spread to 150 countries.
Sircam: A computer worm from 2001 that used counterfeit emails with the subject line, “I send you this file in order to have your advice.”
Explorezip: This worm used fake emails to spread to every machine on thousands of local networks.
Melissa: The most dangerous computer virus in 1999, Melissa sent copies of itself that looked like NSFW pics. The U.S. FBI estimated cleanup and repair costs at $80 million.
Flashback: A Mac-only virus, Flashback infected over 600,000 Macs in 2012 and even infected Apple’s home base in Cupertino, Calif. In 2020, there’s now more malware on Macs than on PCs.
Conficker: This 2009 virus still infects many legacy systems and could do significant damage if it ever activates.
Stuxnet: This worm is reported to have destroyed Iranian nuclear centrifuges by sending damaging instructions.
“Device requires further installation”Aside from corrupted or outdated drivers, the error could also be caused by pending updates, an incorrect version of the Intel PROSet Wireless driver, or checking the wrong event. Whatever the cause is, this post will provide you with some potential fixes that can help you resolve the problem. But before you troubleshoot the problem, ensure that your Windows 10 computer is updated to its latest version and you must also not forget to check that you’re checking the correct event on the Event Viewer. Once you have these things covered, proceed to the instructions below.
“The boot configuration data store could not be opened”while you try to carry out any command on the bcedit.exe, then you’ve come to the right place as this post will guide you on how you can fix this error in Windows 10. This kind of error could pop up if the system is not able to locate the specified file. It is also possible that the requested system device can’t be found or that the boot configuration data store could not be opened. In addition, when you open the System Configuration or MSConfig, you might notice that there is no Boot data, and according to the reports, is that when you try to dual boot the computer, the installer will replace the default bootloader.
Error Code 0x800705b4 is an error that will appear when the computer is not stable, and very critical system files will fail to respond or they will start going missing. This will happen when the computer is not being maintained properly. The problem should be solved immediately to avoid any further damage or loss of data. This error code may be regarded as one of the most severe computer problems that can present itself.
Common symptoms include:
Error CausesWindows 10 update error 0x800705b4 can be caused when the user wants to update their windows system when important dll registries or files are missing or are corrupt. This will also happen when the user is trying to install or uninstall programs in a way that is wrong, or it may be infected with a Trojan virus. Additionally, this error code will be displayed when a PC's drivers are either outdated or installed the wrong way. There could be a registry error, a failure to update by the operating system, or even a device failure to update automatically.
There are several ways to resolve the appearance of error code 0x800705b4 on Windows devices. If you are not familiar with fixing error codes on a computer or are having trouble fixing this one, consider contacting a Windows technician to help with fixing the error. The computer must be run on administrator mode no matter which steps you are taking or which methods you are using. Depending on which version of Windows you are using, the steps for each method may differ slightly, but the basic process will remain the same.
Start the computer in safe mode to begin troubleshooting for error code 0x800705b4. When the computer is starting up, press F8—this will enter the computer into safe mode.
You will now need to manually update your computer's outdated drivers. To do this, click on Start. Then, type in Device Manager into the search box to see if there are any outdated or corrupt issues with the drivers.
This will allow users to find files in Windows that are corrupt, damaged, or lost.
This is the most efficient way to fix any problem or system status. System backup is vital when performing this.
Click on the Start button, and then type in “system restore” inside of the search box. Right click on System Restore, and then choose Run as Administrator. This could also be found in the Control Panel. Now you will choose the time point in which to restore the system. You will be able to choose the recommended or specific restore based on the situation. Now you can review the restore point and then click Finish.
If you wish to always have at your disposal a utility tool to fix these Windows 10 and other related issues when they do arise, download and install a powerful automated tool.
If you consider yourself a power user or you value your privacy then firefox is the browser for you. It is open source and is packed with great features like reporting when your email has been used for a known data breach, it stops annoying pop-up notifications, stops browser fingerprinting, and many more. Firefox is also a cross-platform browser making it a great choice if you want to transfer and use your data across multiple devices with one account. The downside of firefox however is its speed, this browser is the slowest on this list, I guess features and advantages took their tool in the speed department, but if that is not a concern for you and you feel like the positives outweigh some slower speed, grab it here.
Chrome browser has been a game-changer when it was released and even today some of its features are still great and needed. It is packed with some great features like tab freezing, for example, it is cross-platform meaning that also as firefox you can change data between browsers on different devices. it is a very expandable browser with tons of extensions and its speed performance is very very good. The downside of Chrome are two things sadly, one of them is its hunger for RAM, the browser takes a big chunk of RAM once it is active and on some older computer with limited RAM it performs slowly, another is telemetry which its sending, in other words, other browsers don’t come with the lingering fear that Google’s just a little bit too involved in all of our lives. But if downsides do not trouble you and you have a decent amount of RAM in your system chrome might be the best solution for you, grab it here and check it out.
Or should I say Microsoft edge 2.0 since this new Edge is completely recoded and rethought, a completely new browser based on chromium. The first version of the edge was an inhouse attempt from Microsoft and it was a disaster, I guess the lesson was learned, and this new edge we have today is a great Browser, it is lightning fast and packed with some great features with one among them standing out I just love, that is the ability to save web pages as applications and truth to be told you have to try this in order to see al great advantages it offers. A very interesting feature is that edge itself wins the speed race from all of the 5 contestants here which is a great surprise. Of course, the downside of annoying Microsoft pushing it to be your default is, well it's Microsoft, as chrome is tied to Google so is edge tied to Microsoft, and the same dreaded feeling that big MS is watching you. If however, you do not concern yourself with these kinds of things, since it is already part of Windows 10, give it a spin and try it, I am sure you will at least love its blazing speed.
A new kid on the block, relatively unknown Browser Vivaldi offers some great customizable features no other one on this list offers, a very unique and down to each detail customization option, you can literally tweak each and every aspect of this browser making it best customizable and personal browser ever. How it is also based o chromium, every chrome extension works in it naturally. It is very good in speed and constantly updated and developed. The downside, well if you are anything like me, you could spend ages trying to customize it, ages, it has tons of features, and making it really feel and tick as you want can consume a really lot of time. If this thing does not bother you at all, grab Vivaldi here.
Last but not least, we have another relic of the old browser age, the Opera browser. Packed with great security and great in-house features like a built-in VPN, built-in ad blocker, built-in crypto wallet, etc this browser seems like a swiss army knife. Opera is full of features and it shows once you start using it. The downside of opera is that its look and feel are specifically tailored to a certain type of user and not everyone will find that appealing or attractive, add some great but hidden and hard to come by features and it may go unnoticed. However, I think you should really give it a go since it definitely deserves more attention than it gets. Grab it here and check it out.