13 Dangerous Computer Viruses which can Mess Up your Computer

Computer viruses and malware are continuously evolving/upgrading day by day. Now Keeping data safe has become even more difficult. If your PC is not protected properly then the chance will be the increase of being attacked by a hacker or cybercriminal.

Nowadays viruses are the most common way used by hackers or cybercriminals.

1. Fake Windows Updates (Hidden Ransomware)

Hackers are increasingly sending emails that instruct readers to install urgent Windows OS updates. The emails trick readers into installing the “latest” Windows updates, which are ransomware ‘.exe’ files in disguise.
The ransomware contained in these emails is known as “Cyborg”. It encrypts all of your files and programs and demands a ransom payment to un-encrypt the files.
Unfortunately, many email service providers and basic antivirus software aren’t good to detect and block these emails. this is why you need to be using an antivirus that gives proper internet security, protecting you from dangerous emails.

2. The Klez Virus

Klez Virus makes its way to the digital world in late 2001. This virus infects the victim’s computer through an e-mail message, replicated itself then sent itself to people in the email address book. On further testing, it’s found that the Klez Virus acts as a common virus. However, this virus is capable to disable the antivirus system that’s installed on the victim’s computer.
Hackers later modified the Klez virus to make it more powerful. The virus was programmed to spam people with multiple e-mails that clog an inbox in short order.

3. CryptoLocker

CryptoLocker is a variety of trojan horse ransomware targeted at computers running Windows. It uses several methods to spread itself, like email, and once a computer is infected, it'll proceed to encrypt certain files on the hard disk and any mounted storage connected to it with RSA public-key cryptography.
While it's easy enough to remove the malware from the pc, the files will still remain encrypted. The only way to unlock the files is to pay a ransom by a deadline. If the deadline isn't met, the ransom will increase significantly or the decryption keys are deleted.

4. Zeus Gameover

Zeus virus is part of the “Zeus” family of malware and viruses and it was first discovered in 2011. The virus is a kind of malicious software that targets Microsoft Windows. Spam messages and drive-by downloads are two main methods of infection.
The main purpose of the Zeus virus is to access the victim’s sensitive bank account details and steal all of the victim’s funds. The virus can bypass centralized servers and make independent servers to send sensitive information and a victim cannot even trace his/her stolen data. Also in some cases, Zeus can download ransomware that encrypts your files and demands money in exchange for unlocking them.
The simplest way to get free of the Zeus virus is to use antivirus software as well as a malware removal tool.

5. Artificial intelligence (AI) Attacks

As more tools become available to developers who want to program AI scripts and software, hackers can use this same technology to carry out devastating cyberattacks.
Although cybersecurity companies are using Artificial intelligence and machine learning algorithms to help combat malware, these technologies also can be exploited to hack devices and networks on a huge scale. 
Cyberattacks can often cost cybercriminals a lot in terms of time and resources. So, with the expansion of AI and machine learning technologies, we can only expect hackers to develop highly-advanced and destructive AI-based malware in 2020 and beyond.

6. Leap-A

Leap-A which is known as Oompa-A debuted in the year 2006. Leap-A virus targeted Mac systems and it used the iChat instant messaging app to propagate across vulnerable Mac computers. After infecting the Mac computer, the virus spread itself to all iChat contacts and sends a message to every and each person.
The message that the virus sents contains a corrupted file that looks like a JPEG image. That corrupted file destroyed many Mac Computer and this is often where Leap-A became popular.

7. ILOVEYOU

ILOVEYOU virus originated in the Philippines, began to infect computers on May 5, 2000. The virus spreads by email with the message line “ILOVEYOU” and an attachment, “LOVE-LETTER-FOR-YOU.txt.VBS” If the attachment was opened, a Visual Basic script was executed, and therefore the computer was infected. it's considered one of the most virulent computer viruses ever created. It managed to wreak havoc on computer systems everywhere in the world with around $10 billion worth of damages. 10% of the world’s computers were believed to have been infected. it had been so bad that governments and enormous corporations took their mailing system offline to stop the infection.
To stay safe from virus attacks like ILOVEYOU, there's a dire you need to install a good virus removal program.

8. Flashback

Though not as damaging because the rest of the malware on this list, this is one among the few Mac malware to have gain notoriety because it showed that Macs aren't immune. The Trojan was first discovered in 2011 by antivirus company Intego as a fake Flash install.
In its newer incarnation, a user simply needs to have Java enabled (which is likely the majority of us). It propagates itself by using compromised websites containing JavaScript code that will download the payload. Once installed, the Mac becomes a part of a botnet of other infected Macs.

9. IoT Device Attacks

As the popularity of IoT (Internet of Things) devices grows in 2020 — things like smart speakers and video doorbells — hackers are looking to exploit these devices for valuable information.
There are multiple reasons why hackers prefer to target IoT devices. For one, most IoT devices don’t have enough storage to install proper security measures. These devices often contain easy-to-access data like passwords and usernames, which then can be used by hackers to log in to user accounts and steal valuable information, like banking details.
Hackers can use internet-based cameras and mics to spy on and communicate with people — including young children via smart baby monitors.
These devices can act as weak points in a corporation’s network, meaning hackers can gain access to entire systems through unsecured IoT devices — spreading malware to other devices across the network.

10. Nimba

Nimda first appeared on September 18, 2001, and it spread through the internet rapidly. In fact, it only took 22 minutes from the moment Nimda hit the internet to reach the top of the list of reported attacks. The main purpose of the Nimda virus was to bring Internet traffic to a crawl. By creating a backdoor in the victim’s OS, it gives access to the attacker to the same level of functions. Also, if the victim was the administrator for the machine, the attacker would have full control. Nimda worm became a distributed denial of service (DDOS) attack after the spread of the Nimda virus which caused come networks to crash as more of the system’s resources became fodder for the worm.
According to data from the Cooperative Association of Internet Data Analysis, the Nimda virus infected nearly 160,000 systems. The virus code includes the text: Concept Virus(CV) V.5, Copyright(C)2001 R.P.China.

11. Sasser

A Windows worm first discovered in 2004, it was created by computer science student Sven Jaschan, who also created the Netsky worm. While the payload itself may be seen as simply annoying (it slows down and crashes the pc while making it hard to reset without cutting the power), the consequences were incredibly disruptive, with many computers being infected, and important, critical infrastructure affected.
The worm took advantage of a buffer overflow vulnerability in the Local Security Authority Subsystem Service (LSASS), which controls the security policy of local accounts causing crashes to the pc. it'll also use the system resources to propagate itself to other machines through the internet and infect others automatically.

12. Mydoom

MyDoom, the first version of the worm, appeared on January 26, 2004. It spread via email and through a peer-to-peer network. This virus originated from Russia and is written in C++ programing language. The virus creates a backdoor in the victim’s computer’s OS. On Feb 1, 2004, it caused the virus to start a denial of service (DoS) attack and on Feb 12, it stopped distributing itself. Even after the virus spread, the backdoors created during the initial infections remained active. MyDoom, like ILOVEYOU, is a record-holder and was the fastest-spreading email-based worm ever.
MyDoom was an odd one because it hit tech companies like SCO, Microsoft, and Google with a Distributed Denial of Service attack. In 2004, roughly somewhere between 16-25% of all emails had been infected by MyDoom.

13. News Malware Attacks

Cybercriminals often use current news stories and global events to target people with malware.
One example is hackers using the wave of the COVID-19 (Coronavirus) outbreak to focus on individuals with malware. Hackers send emails that are disguised as legitimate information about the outbreak. Readers are prompted to click a link read more about the information, but the link contains malware that copies the files on your device and steals your personal information.
Research currently focuses on the spread of this malware in Japan. Still, it'll become an issue worldwide during any quite newsworthy outbreak.