A computer virus is a malicious software program designed to infect a computer system and cause damage or disrupt normal functioning. It can replicate itself and spread to other computers.

1. File Infector Virus: Attaches to executable files.


2. Macro Virus: Infects documents created by programs like MS Word or Excel.


3. Boot Sector Virus: Infects the boot sector of a storage device.


4. Polymorphic Virus: Changes its code to avoid detection.


5. Resident Virus: Embeds itself in the computer's memory.

• Melissa virus


• ILOVEYOU virus


• Michelangelo virus

1. Corrupt files or delete data.


2. Slow down the system.


3. Cause system crashes.


4. Spread to other computers.

1. Infected Storage Media: Such as diskettes, CDs, USB drives that contain infected files.


2. Email Attachments: Opening infected attachments can spread viruses.


3. Internet Downloads: Downloading programs or files from untrusted websites.


4. Pirated Software: Illegal or cracked software often contains viruses.

1. Sudden slowdown of the computer.


2. Files or programs become corrupted or disappear.


3. Unusual error messages.


4. Unexpected pop-ups or messages.


5. Programs running without user command.

1. Using antivirus software to scan files and systems.


2. Monitoring unusual system behavior.

1. Always install and update antivirus software.


2. Avoid opening unknown email attachments.


3. Do not download software from unreliable sources.


4. Regularly update your operating system.


5. Backup important data regularly.