What is virus?

A computer virus is a type of malware that replicates itself by modifying other computer programs and inserting its own code into them. It can spread autonomously and infect vulnerable systems, causing various damages like deleting files, crashing systems, or stealing data.

Computer viruses are designed to disrupt computer operations and can be harmful to the performance of devices.

The structure of a computer virus includes components like search and copy mechanisms for propagation, payload activation triggers, and the payload itself which can be harmful or benign.

The life cycle of a computer virus consists of phases such as the dormant phase, propagation phase where it replicates, triggering phase when activated, and execution phase where the payload is released.

Some common types of computer viruses include:

File-infecting Virus: These viruses attach themselves to executable programs, infecting files with .exe or .com extensions. They can overwrite host files or damage hard drive formatting.

Macro Virus:

Typically found in programs like Microsoft Word or Excel, these viruses are stored as part of a document and spread when files are transmitted to other computers, often through email attachments.

Browser Hijacker:

This virus alters browser settings and redirects users to malicious websites, posing threats like changing the default home page of browsers.

Web Scripting Virus:

These viruses target popular websites, overwrite code on a website, and insert links that can install malicious software on devices.

Boot Sector Virus:

Once common when computers booted from floppy disks, these viruses are now found in physical media like external hard drives or USBs. They automatically load into memory, enabling control of the computer.

Polymorphic Virus:

Capable of evading antivirus programs by changing codes each time an infected file is executed.

Resident Virus:

Stores itself in a computer's memory, infecting files and interfering with the operating system, leading to file and program corruption.

Some signs that your computer may be infected with a virus include:

Unexpected pop-up windows.

Random sounds or warning beeps.

Unexplained changes to files or folders.

Slow computer operation, especially if the hard drive light is constantly on or the fan is running at full speed.

Missing files or altered file content.

Legitimate antivirus software alerting you about unauthorized connections.

Pornographic images appearing unexpectedly.

Pop-up ads for unfamiliar sites.

Frequent crashes or freezing of the system.

To remove a virus from your computer, follow these steps:

Scan your computer with antivirus software: Run a full system scan using a reputable antivirus program. This will help detect and remove any viruses that may be present on your computer.

Use Microsoft Safety Scanner:

Microsoft offers a free online tool that scans and helps remove potential threats from your computer. You can download it from the Microsoft Safety Scanner website and run a scan to detect and remove any viruses.

Use the Windows Malicious Software Removal Tool:

This tool is designed to remove specific prevalent malware from your computer. You can download it from the Microsoft Knowledge Base and follow the instructions to remove the malware.

Manually remove rogue security software:

If the rogue security software cannot be detected or removed by using Microsoft Safety Scanner or the Windows Malicious Software Removal Tool, you can manually remove it by following these steps:

Restart your computer and press F8 during the startup process to enter Safe Mode.

Remove the rogue security software from the Start menu or All Programs.

Delete the rogue security software's folder from the Program Files directory.

Restart your computer and run a full system scan to ensure that the virus is completely removed.

Run Microsoft Defender Offline:

This is an anti-malware tool that helps remove difficult-to-eliminate viruses that start before Windows. It can be run in Safe Mode or from a bootable USB drive.

To prevent your computer from getting infected with a virus, consider the following tips:

Keep your computer up to date: Regularly update your operating system and software to ensure you have the latest security patches that can protect your system from vulnerabilities.

Avoid suspicious websites:

Be cautious of clicking on links from unfamiliar or suspicious websites as they may contain malicious content that can infect your computer.

Install antivirus software:

Use reputable antivirus software and keep it updated to detect and remove viruses from your computer. Run regular scans to ensure your system is clean.

Be cautious with email attachments:

Avoid opening email attachments from unknown senders or clicking on links in emails that seem suspicious. These can be common ways for viruses to infect your computer.

Backup your data:

Regularly back up your important files on an external hard drive or cloud storage to prevent data loss in case of a virus infection.

Use strong passwords:

Create complex passwords and change them regularly to enhance the security of your accounts and prevent unauthorized access to your computer.

Virus and Malware

The main difference between a virus and malware lies in their scope and characteristics. Malware is an umbrella term for any malicious software designed to infect and harm a host system or its user, encompassing viruses, spyware, adware, ransomware, and other harmful software types. On the other hand, a virus is a specific type of malware that self-replicates by copying itself into other programs or documents to spread autonomously.

Key Differences:

Malware is a broad category that includes various types of harmful software, while a virus is a specific type of malware that replicates itself.

Viruses are designed to copy themselves and spread widely like biological viruses infecting hosts, while malware encompasses a wider range of harmful software beyond self-replicating viruses.