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.
In 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.
Need to up your remote work security game before there’s another entry on the list of most deadly computer viruses? See our guide: How to Work Remotely and Securely
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.
Can your printer get a virus? See our cool infographic: The State of Printer Security
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.
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From the Terms of Use: You hereby acknowledge and agree that by using an MS Product you may be exposed to Content that may be offensive, indecent or objectionable in your community […] MS Products are exposed to various security issues, and should be regarded as insecure. By accepting this Agreement, you acknowledge and accept that the MS Products and any information you download or offer to share by means of an MS Product, may be exposed to unauthorized access, interception, corruption, damage, or misuse, and should be regarded as insecure. You accept all responsibility for such security risks and any damage resulting therefrom.
This extension has been marked as a Browser Hijacker by several anti-virus scanners and has been flagged for optional removal. It is not considered malicious but many users wish to remove it due to the above reasons.
Code 43, Device Manager Error, is reported when Windows doesn’t recognize a hardware device such as the video card, USB, printer, or any other piece of external hardware attached to your PC.
The Device Manager stops the hardware if it reports some kind of unspecified problem. It is mostly displayed in the following format:
“Windows has stopped this device because it has reported problems. Code 43”
Code 43 can be triggered due to several reasons. However, 95% of the times it is related to the device driver problems such as:
Driver problems pop up when either new driver versions are available or drivers become damaged due to some underlying reasons like viral infections.
Other than driver problems, code 43 can also pop up when you install and remove the software. This can cause hardware conflict in the registry, altering driver communication.
Code 43 can hamper your ability to use your desired device smoothly. Although Code 43 is not a fatal error code like Runtime and BSoD errors, it is still advisable to resolve it immediately to avoid inconvenience.
You can sometimes bypass error code 43 temporarily by a simple PC reboot but this will not fix the problem permanently. For a permanent fix, try the methods given below.
To help you repair code 43 permanently from your PC, below are some of the best, easy perform, and effective solutions. Simply follow the steps to get rid of code 43 from your PC.
This is one way to find the exact nature of the problem that spurred error code 43 to pop up. To launch and run the Troubleshoot Wizard, here’s what you need to do:
The Wizard will diagnose the problem and provide you a solution to resolve it, all you have to do from there is to follow the Wizard’s instructions
If for some reason Method 1 doesn’t work, another solution would be to check the hardware documentation for more information about diagnosing the problem.
If the underlying reason for code 43 is related to driver problems, then the best way to resolve it is to uninstall faulty drivers and then reinstall new drivers. One of the many ways to uninstall drivers is:
Identifying and updating new driver versions manually can be both frustrating and time-consuming especially if you are in a rush and no computer whiz.
Also, after you update the drivers, you need to keep checking them time and again to ensure they don’t become outdated. You need to update them every time new versions are available which can be stressful.
To avoid this hassle by repairing code 43 permanently, download DriverFIX. This is an innovative and user-friendly device driver software program exclusively designed to resolve all kinds of driver problems.
Whether code 43 occurs on your PC due to missing or outdated drivers, DriverFIX can resolve the problem easily.
The intelligent programming system embedded in this software enables it to detect problematic and outdated drivers in seconds.
It matches new and compatible versions and updates the drivers immediately, automatically, and on a regular basis in just a few clicks. This resolves code 43 and also ensures that all your drivers remain up to date.
DriverFIX is compatible with all Windows versions.
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“Microsoft Windows Network: You can’t connect to the file share because it is not secure. This share requires the obsolete SMB1 protocol, which is unsafe and could expose your system to attack. Your system requires SMB2 or higher.”In this post, you will be guided on how to check if the SMB2.0 version can be installed on your Windows 10 computer. To get started, follow the steps below. Step 1: Tap the Win + X keys to open the Device Manager. Step 2: After that, click on the Windows PowerShell (Admin) option. Step 3: In the Windows PowerShell window, type the following command and hit Enter:
Get-SmbServerConfiguration | Select EnableSMB2ProtocolNote: After entering the command, you will see the following content on your screen which means that your Windows 10 computer is now capable of running the SMB2 protocol Now all that’s left for you to do is to enable the SMB 2 protocol on your Windows computer by enabling the SMB 1 protocol first and then upgrading it to SMB 2 afterward. Refer to the steps below for more details. Step 1: Tap the Win + I keys to open the Settings app. Step 2: Then type in “control panel” in the search area and click on Control Panel from the search results. Step 3: After opening Control Panel, click on Programs. From there, select the “Turn Windows features on or off” option under the larger menu of Programs and Features. Step 4: After that, Windows Features will appear on your screen. And from there, make sure that you select SMB 1.0/CIFS File Sharing Support and then click on OK. Step 5: Now let it install all the required files and then restart your computer to apply the changes made successfully. After your computer has restarted, the SMB 2 protocol should now be supported on your Windows 10 computer. Note: On the other hand, you can also enter the following command in the Windows PowerShell window. Just make sure you have admin rights to enable it.
Set-SmbServerConfiguration –EnableSMB2Protocol $true