Common Viruses in Computer: You should know about these

Computer viruses remain a major threat in the digital age, with new strains emerging constantly to wreak havoc on personal and business systems alike. While advanced cybersecurity measures have become more widespread, viruses still manage to infect millions of computers every year, causing data loss, system crashes, and privacy breaches. Let us see the common viruses in computers and their details in this post.

Every user of the computer or pc has heard about the term virus in the computer terminology. The virus is nothing but a malicious file that affects the regular operations of the computer and slows down.

Computer working speed and its performance duplicate the files and also carry malicious activities that are unhealthy for the computer’s health.

As technology has become an integral part of our lives, threats to our digital security have also emerged. Computer viruses are malicious software programs that can infect and damage computers. They are designed to replicate themselves and spread from one computer to another, causing various issues ranging from minor annoyances to severe system crashes.

What is a computer virus?

A computer virus is a type of malware specifically designed to replicate itself and spread from one computer to another. It attaches itself to legitimate programs or files and can execute malicious actions when these files are opened or run. Hackers frequently produce computer viruses with the intention of causing harm to data, stealing personal information, or gaining illegal access to systems.

How are the computer viruses spreading?

The line between viruses and malware can blur. Understand the key differences to effectively safeguard your computer from various cyber threats. Common computer viruses can spread through various means, including:

• Email attachments: Viruses can be disguised as innocent-looking email attachments. When a user opens the attachment, the virus gets activated.
• Infected files: Sharing infected files via external storage devices like USB drives can spread viruses to other computers.
• Downloads: Downloading files or software from untrusted sources can expose your computer to viruses.
• Network vulnerabilities: Weak network security can provide an entry point for viruses to infect multiple computers within a network.

Types of computer viruses

Several types of computer viruses can cause different types of damage. Common viruses in computers can help you recognize and protect against them. Here are some common types:

1. Trojan Horse Virus

Trojan horses are one of the oldest and most notorious types of computer viruses. These deceptive programs disguise themselves as legitimate software, enticing users to install them unknowingly. Once activated, Trojan horses can grant remote access to your system, steal sensitive information, or even install other malware.

Symptoms: Unusual system behavior, sluggish performance, and the appearance of unfamiliar programs or processes.

2. Worm Virus

Worms are self-replicating viruses that spread rapidly across networks and the internet, consuming bandwidth and potentially causing system crashes or data loss. Unlike Trojan horses, worms don’t require user interaction to propagate, making them a significant threat to unprotected systems.

Symptoms: Network congestion, slow internet connectivity, and unexpected file transfers or email attachments.

3. Ransomware Virus

Ransomware has become a cybercriminal’s weapon of choice in recent years. This insidious virus encrypts your files and demands a ransom payment to regain access. If the ransom is not paid, your data may be permanently lost or leaked online.

Symptoms: Locked files and folders, ominous ransom notes or pop-ups, and system slowdowns or crashes.

4. Adware and Spyware

Adware and spyware are often bundled with free software downloads, injecting unwanted advertisements or tracking your online activities without consent. While not as destructive as some other viruses, they can compromise your privacy, slow down your system, and serve as a gateway for more severe malware infections.

Symptoms: Excessive pop-up ads, browser redirects, and unauthorized data collection.

5. Rootkit Virus

Rootkits are stealthy viruses designed to gain administrative-level access to your system, making them notoriously difficult to detect and remove. Once installed, rootkits can conceal malicious activities, steal sensitive data, or facilitate further malware infections.

Symptoms: Unusual system behavior, missing files or processes, and unexplained network traffic.

6. Botnet Virus

Botnets are networks of compromised computers controlled by cybercriminals, often used for distributed denial-of-service (DDoS) attacks, spamming, or cryptocurrency mining. If your system is part of a botnet, it can be used for nefarious purposes without your knowledge.

Symptoms: Sluggish performance, increased internet bandwidth usage, and unexplained network activity.

7. Browser Hijacker

As the name suggests, browser hijackers hijack your web browser, altering your default homepage, search engine, or other settings without permission. These viruses can bombard you with unwanted advertisements, track your online activities, or redirect you to malicious websites.

Symptoms: Unexpected changes to your browser settings, unwanted toolbars or extensions, and frequent pop-ups or redirects.

8. Mobile Malware

With the rise of smartphones and tablets, mobile malware has become an increasingly prevalent threat. These viruses can steal personal data, rack up charges through premium services, or even transform your device into part of a botnet.

Symptoms: Unexplained data usage, rapid battery drainage, and unauthorized charges or activities.

9. Macro Virus

Macro viruses take advantage of the powerful scripting capabilities found in widely used office software, such as Microsoft Word or Excel. These viruses can corrupt your documents, steal data, or even spread to other systems through infected files.

Symptoms: Unusual document behavior, sluggish performance, and unexpected file modifications or deletions.

List of Common viruses in computer

1. I love you

I love you was one of the most affected viruses in computer history. It affects more than 1 billion computers not only personal computers. This virus affected government computers and other confidential computers used by government officials.

It comes with an email named subject as I LOVE YOU and have an attachment with the name of LOVE-LETTER-FOR-YOU.TXT.VBS

After click on the file was downloaded and it was installed in the background. The file runs in the background and sends your personal data to all contacts in your windows address book and duplicates your files randomly. Finally, it corrupts your computer along with data.

The virus originated in Pentagon, which was situated in Manila, Philippines, on May 5, 2000.  From there onwards, it moves first towards Hong Kong, then to Europe, and finally to the United States.

The virus damaged approximately 5-9 billion us dollars worthy data in the official computers.

With the effect of this virus, the Pentagon and British parliament and CIA completely shut down their email systems until the problem was resolved.

So don’t open the email if you received by the name ILOVEYOU and with the attachment of the LOVE LETTER.txt.vbs.

If you open this email, your personal files will be in trouble and you have to forget about it and buy a new pc.

2. Code red

This was another type of virus that affects the computer and do a lot of damage at once upon a time in the global arena. The name of the virus also has a story.

It was exposed by the two-eyed digital security employees. It was named Code Red because, at the time of that virus discovery,. They were drinking code-red mountain dew.

What is Code Red?

Code Red was a computer worm observed on the Internet on July 15, 2001. It attacked computers running Microsoft’s IIS web server. The Code Redworm was first discovered and researched by eEye Digital Security employees Marc Maiffret and Ryan Permeh when it exploited a vulnerability discovered by Riley Hassell.

The size of that virus was just 3569 bytes only. But once it was infected then it starts their work and duplicates files in your PC drives itself.

It fills the entire hard disk with duplicated files and also opens the backdoor to the server. Hackers can gain access to it through the compromised PC’s backdoor.

Finally, it leads to the disrupt the functions of the pc and collapses the PC.

Approximately 1-2 million servers were impacted by this virus, resulting in losses of about $2 billion.

How did the Code Red virus spread?  It leaves the message with the CONTENT HACKED BY CHINESE After seeing this message, you just have to forget about your data and reset it.

3. Melissa

It was named after a dancer from Florida. David L. Smith was its creator in 1999. It was an infected Word document posted on the alt.sexnet group.

In the 1990s, the Melissa virus, also known as Kwyjibo or Kwejeebo, infected 20% of the world’s computers.

It said that the list of passwords for pornographic sites. This makes the users enthusiastic and downloaded it.

When documents infected with the Melissa virus were opened, embedded macros would automatically send the same document to the first 50 contacts in the victim’s address book.

This will increase the mail trafficking and sometimes it will corrupt the infected pc. Mostly it interrupts the functions of the pc and damages the pc working.

Smith was arrested by the FBI while trying to locate the document, and he later worked with them to capture the other virus developers.

He was put behind bars for only 20 months and paid fine of 5000 dollars as a penalty and it causes approximately 80 million dollars damage.

4. Sasser

Sasser is another type of virus that affects computers. This windows worm was first discovered in 2004.

Science student Steven Jascha is the creator of it. It slows down the working speed of the computer and also affects the functions of the computer.

It will also spread itself to another computer through the internet.

An update was released to patch this bug.  Even though an update was released, Thousands of computers did not update.

The final result is the virus infected millions of computers like airline news agencies, public transport, hospitals. The estimated damage is nearly 18 billion dollars.

5. Zeus

It was a trojan horse. It will infect the windows computers. The main theme of this virus code is to steal the credentials like login id and passwords of large multinational corporations like Facebook, Amazon, Oracle, a bank of America, etc.

It affects more than 25% of the United state’s computers. It estimates that more than 1 million computers were infected, and more than 70 million pieces of data were stolen.

More than 100 people were arrested who were involved in this operation.

Once this Trojan was entered into the pc, then all your login credentials (Usernames and Passwords) were going into the third parties. They can steal all your data and money from your account.

6. Conficker

Another name for this virus was down up. It was developed by using the loopholes in the computer’s Operating system to create a botnet.

What is BotNet?

Botnet is a software intentionally designed to cause damage to a computer, server, client, or computer network.It may allow an attacker to access user’s personal information such as banking information, passwords, or personal identity.It can infect other devices connected to the network.

This virus infects more than 9 millions of computers all over the world.

The main target of this virus is to hack government computers and business people’s pics.

It was one of the biggest worm infections. It has done more than 9 billion us dollars damage.

It automatically allows the installation of the virus without administrator permission.

Signs of a computer virus infection

Detecting a computer virus infection is essential for timely action. Here are some signs that may indicate your computer is infected:

• Slow performance: If your computer suddenly becomes slower than usual, it may be a sign of a virus.
• Unexpected crashes: Frequent system crashes or program freezes could be a symptom of a virus infection.
• Pop-up ads: An increase in unwanted pop-up ads, even when you’re not browsing the internet, can be a sign of adware or malware.
• Missing or modified files: If files or folders suddenly disappear or their content has changed unexpectedly, it may indicate a virus infection.
• Unusual network activity: Excessive data usage or network traffic when you’re not actively using the internet could indicate a virus.

Consequences of a computer virus infection

With data breaches on the rise, protecting your information is more important than ever. Discover how to choose between free and paid antivirus software to ensure maximum data security. Computer virus infections can have severe consequences, including:

• Data loss: Viruses can delete or corrupt files, leading to irreversible data loss.
• Identity theft: Some viruses are designed to steal personal information, such as credit card details, passwords, or social security numbers.
• System instability: Viruses can disrupt system operations, leading to crashes, freezes, or the inability to start the computer.
• Unauthorized access: Certain viruses provide hackers with remote access to infected computers, enabling them to control or use the system for malicious activities.

How to Protect Your Devices from virus infection?

While the threat landscape is ever-evolving, there are several essential steps you can take to safeguard your devices and data from these common computer viruses:

1. Install and regularly update antivirus software: Reputable antivirus solutions from trusted vendors can detect and remove many known viruses, as well as provide real-time protection against new threats.
2. Keep your software up-to-date: Critical security patches are frequently included in software updates, addressing vulnerabilities that viruses may exploit. Ensure that your operating system, web browsers, and other applications are always running the latest versions.
3. Exercise caution with email attachments and downloads: Be wary of unsolicited email attachments or downloads from untrusted sources, as these are common entry points for viruses.
4. Use strong passwords and enable two-factor authentication: Robust passwords and multi-factor authentication can prevent unauthorized access to your accounts and devices, reducing the risk of virus infections.
5. Regularly back up your data: Maintaining regular backups of your essential files and data can ensure that you can recover in the event of a virus infection or other data loss incident.
6. Enable firewalls and keep them updated: Firewalls can help prevent unauthorized access to your system and block malicious network traffic, providing an additional layer of protection against viruses and other threats.
7. Stay informed about the latest threats: Stay up-to-date on the latest virus threats and cyber trends by following reputable security resources and industry news. This awareness can help you identify and mitigate risks proactively.

By understanding the common computer viruses and implementing these essential security measures, you can significantly reduce the risk of falling victim to these malicious codes and protect your valuable data and systems from harm.

How to remove computer viruses

Unsure if that strange pop-up is a virus? Learn the telltale signs of a computer virus infection and discover free tools to remove them.

Some malware infections can be difficult to remove with a basic antivirus scan, so you may need specialized Trojan removal tools.

If you suspect your computer is infected with a virus, take the following steps to remove it:

• Run a full scan with your antivirus software to detect and remove the virus.
• Disconnect from the internet to prevent further damage or unauthorized access.
• If your antivirus software cannot remove the virus, seek professional help or use specialized virus removal tools.
• Once the virus is removed, update your operating system and all software to the latest versions to patch vulnerabilities.

Frequently Asked Questions (FAQs)

Conclusion

Computer viruses pose a significant threat to individuals and organizations, causing various issues ranging from inconvenience to severe data breaches. In today’s remote work environment, cloud-based security solutions offer a powerful alternative to traditional antivirus software. Explore the pros and cons to find the best fit for you.

You can protect your computer and personal information from these malicious programs by understanding the types of viruses, signs of infection, and preventive measures.

To avoid virus attacks, you need to install better Internet security suites on your computers. Updating the operating system with recent patches is very important.

You should check the software terms and conditions before installing them on the PC. The common viruses on computers in 2025 are very dangerous.

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A proactive approach to cybersecurity can significantly mitigate the risks posed by these viruses. By implementing robust antivirus software, keeping your software updated, exercising caution with downloads and email attachments, using strong passwords and multi-factor authentication, maintaining regular backups, enabling firewalls, and staying informed about the latest threats, you can fortify your digital defenses and protect your valuable data and systems.

The battle against computer viruses is an ongoing one, requiring vigilance, proactive measures, and a commitment to cybersecurity best practices. By taking the necessary precautions and staying informed, you can navigate the digital landscape with confidence, minimizing the risk of falling victim to these malicious codes and safeguarding the integrity of your devices and data.

Cybersecurity is a shared responsibility, and every individual and organization plays a crucial role in mitigating the global impact of computer viruses. By embracing a security-conscious mindset and implementing the strategies outlined in this guide, you can contribute to a safer and more secure digital ecosystem for all.