While computer viruses are still not as dangerous as real-life viruses, they can still cause significant damage if left undiscovered and allowed to infect large numbers of computers—just like their natural counterparts. Over the past few years, viruses and other similar types of mass cyberattacks have caused significant real-world harm to people and businesses around the world, often in the form of loss of important data and financial losses.
10. Stuxnet
The Stuxnet worm has been discovered June 17, 2010 VirusBlokAda, a malware program widely considered one of the most sophisticated cyberweapons ever created, was designed to attack industrial control systems, particularly those used in Iran's nuclear program. Due to its aggressive nature, the worm was able to penetrate the country's computer networks and spread rapidly, soon expanding beyond its intended target.
Stuxnet was a type of cyberattack known as a "worm," capable of self-replicating and spreading from one computer to another without human intervention. In the case of the Iranian nuclear program, Stuxnet was specifically designed to target centrifuges used for uranium enrichment, causing them to malfunction. The worm reportedly successfully infected thousands of computers and delayed Iran's nuclear program for several years, particularly by sabotaging systems on nuclear facility в Natanz .
9. My thoughts
MyDoom, also known as Novarg , is a malicious computer program discovered in January 2004. It is a worm-type virus that spreads through email attachments, file sharing networks and other channels. Once infected, MyDoom can use it to send spam, launch denial-of-service attacks, and collect confidential information, as well as a variety of other malicious applications.
MyDoom typically arrives in emails with seemingly legitimate subject lines, often tricking users into downloading and running malicious code. In its early days, it caused significant damage and disruption, infecting millions of systems and costing an estimated $38 billion in losses.
MyDoom is also responsible for a number of high-profile denial-of-service attacks, including against Microsoft , causing their websites to be inaccessible for several days. According to one estimate, the virus infected approximately 1 of 12 emails at their peak, making it one of the largest cyberattacks in history.
8. Klez
Virus Klez was a mass-mailing worm first discovered in December 2001 . Its first variant was able to spread via email attachments and Internet Explorer, primarily affecting computers running Microsoft Windows. Since then, several advanced variants have been discovered, including those that can easily spoof email addresses from legitimate sources.
Klez virus and its options Klez is particularly dangerous due to its ability to modify or delete files on an infected computer. It can also steal email addresses and passwords, making it a serious threat to the data stored by users of personal and work computers. Some versions of Klez are even capable of disabling antivirus software and creating backdoors for hackers to access the machine, leading to more serious crimes. The Klez virus caused global damage in the early 2000s, infecting millions of computers and email servers worldwide.
7. So big
The Sobig virus first started infecting computers in 2003. It was a type of computer worm that used email and shared network folders to quickly spread to other computers. Sobig even had the ability to create its own server, allowing it to send infected emails to thousands of users without a host email account. At the time, it was also called the fastest email virus outbreak in history, far surpassing the previous one. record, installed by Klez.
Sobig specifically targets computers running Microsoft Windows. Like other successful viruses, it exploits trusted email networks for propagation, particularly through email attachments. At its peak, over 1 million copies of Sobig were detected in emails worldwide, according to digital security firm MessageLabs Inc. Beyond the financial losses, the virus also had an immeasurable impact on individuals, who lost valuable data or documents in the attack.
6. Zeus
Zeus was a type Trojan A virus first discovered during a cyberattack on the US Department of Transportation, Zeus is a financial or banking virus designed to steal sensitive information from infected computers, such as banking credentials, credit card numbers, and other personal data. While the Zeus Trojan can spread in a variety of ways, it primarily spreads through email attachments, malicious downloads, or vulnerabilities in web browsers and other online software.
Zeus can remain hidden and undetected for long periods of time by infiltrating a computer or security system and continuously collecting sensitive data to send to attackers. Later versions were even capable of keylogging , take screenshots, and steal login credentials from user activity. Zeus is known to target financial institutions, government agencies, and corporations, making it a serious threat to both individual users and large organizations.
5. CryptoLocker
CryptoLocker is currently a fairly well-known type of malware that encrypts victims' files and demands payment in exchange for a decryption key or variant thereof. It can be distributed in a variety of ways, typically through email attachments, file-sharing sites, and downloads . CryptoLocker primarily targets Windows users and is known to spread quickly across networks if left unchecked.
Once installed on the victim's computer, the malware encrypts files using a strong encryption algorithm, making them inaccessible without a password or key known only to the hacker. They then demand payment in exchange, usually in the form of Bitcoin or other cryptocurrencies. Depending on the victim and the attacker, the ransom can range from several hundred to several thousand dollars.
CryptoLocker is what we know as ransomware - a special type of malware that annually causes damage to billions dollars worldwide. It can even shut down systems critical to public safety and well-being, such as hospitals and government agencies, until a ransom is paid, making it even more dangerous in the broader scheme of things.
4. PlugX
PlugX is a type remote access Trojan (RAT) used by cybercriminals to certain a type of cyberattack known as an Advanced Persistent Threat (APT). An RAT is malware that gives attackers remote access to a victim's computer, allowing them to control his , as if they were physically present. PlugX is typically delivered through spear-phishing emails or software vulnerabilities. Once installed, it can give attackers complete control over the infected system, allowing them to steal data, execute commands, and install additional malware.
PlugX has military ties, having been used in targeted attacks against government agencies, defense contractors, and other high-value targets. It is particularly effective at evading detection by security software, as it can remain undetected on a compromised system for extended periods of time. Once accessed, an attacker can use PlugX to attack the machine itself or infect it and use it as a launching pad for other, more important systems on the network.
3. NIMDA
The Nimda virus was first discovered in September 2001. It is a complex piece of code that spreads through multiple attack vectors, including email, websites, and shared network resources . The virus combines the best techniques used in worm, virus, and Trojan horse attacks and is capable of infecting both servers and workstations running Microsoft Windows.
To date, the Nimda virus has caused hundreds of millions in losses because it can easily spread through features we use every day, such as email attachments. Unlike other viruses, Nimda did not seek to harm files or the network security of systems. This resulted in a more delayed, chaotic effect, slowing down the entire network for long periods of time, usually through sophisticated attacks like «denial of service» . Nimda is also capable of exploiting known vulnerabilities in web servers, allowing it to infect a large number of computers in a short period of time.
2. Fizzer
The Fizzer worm was first discovered in 2003 by antivirus firm« Kaspersky Lab» . It is a complex and sophisticated malware capable of spreading through multiple channels, such as email, instant messaging, and file-sharing networks. When it was first discovered, Fizzer spread rapidly across the Kazaa network, infecting a large number of computers before being detected.
Once installed on a computer, the Fizzer virus can perform a wide range of malicious actions, such as stealing passwords, credit card numbers, and personal data, as well as disabling security software to open loopholes for more sophisticated actions. Some versions are even known to send infected emails to the victim's contacts, increasing the likelihood of further infection of other systems. Fizzer remains one of the most common viruses in the world, even if it is not as effective as it used to be when P2P file sharing was still popular.
1. Sircam
The Sircam worm was discovered in July 2001 and quickly became one of the most widespread and malicious computer viruses of all time. It was designed primarily to spread via email and shared network resources, using various tricks to lure users into opening infected email attachments. Once installed on a system, the worm would attempt to spread to other computers on the same network, combining malicious actions such as deleting files and sending itself to all contacts in the email address book. user .
Sircam applied billionth It caused damage and infected millions of computers worldwide, largely due to its persistence and high infectivity, as it was often difficult to detect and remove. At its peak, Sircam accounted for a large percentage of internet virus infections, making it one of the largest security threats in history. Fortunately, Sircam is no longer as active as it once was, although it still poses a threat to some legacy Microsoft operating systems that are still in use for certain purposes.