Computer Virus
A computer virus is a type of malicious software (malware) designed to replicate itself and spread from one computer to another. It often attaches itself to legitimate programs or files and can cause a variety of harmful effects on an infected system, ranging from mild annoyances to severe data loss or system damage.
Types of Computer Viruses
Here are some common types of computer viruses:
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File Infector Virus:
- Description: Attaches itself to executable files (.exe, .com) and spreads when the infected program is run.
- Example: ILOVEYOU Virus
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Macro Virus:
- Description: Targets macro languages within applications like Microsoft Word or Excel. It spreads through infected documents.
- Example: Melissa virus.
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Boot Sector Virus:
- Description: Infects the master boot record (MBR) of a hard drive or a floppy disk. It spreads when the computer is booted from the infected drive.
- Example: Michelangelo virus.
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Polymorphic Virus:
- Description: Changes its code every time it infects a new system to avoid detection by antivirus software.
- Example: Storm Worm.
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Resident Virus:
- Description: Installs itself in the system memory and can infect other files and programs while the computer is running.
- Example: Randex, CMJ.
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Multipartite Virus:
- Description: Combines features of different types of viruses (e.g., file infector and boot sector virus) and can spread in multiple ways.
- Example: Tequila virus.
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Web Scripting Virus:
- Description: Targets web browsers by exploiting vulnerabilities in web scripts like JavaScript or ActiveX.
- Example: JS/SpaceStalk.
-
Network Virus:
- Description: Spreads across networks by exploiting vulnerabilities in network protocols and services.
- Example: Nimda virus.
Anti Virus
An antivirus program is a software application designed to detect, prevent, and remove malware, including computer viruses, from a computer system. Antivirus programs use various techniques to identify and mitigate the effects of malware.
Key Features of Antivirus Programs
Real-Time Scanning:
- Continuously monitors the system for any suspicious activity or files, providing immediate protection against new threats.
On-Demand Scanning:
- Allows users to manually scan specific files, folders, or the entire system for malware.
Automatic Updates:
- Regularly updates the virus definitions and program features to protect against the latest threats.
Heuristic Analysis:
- Uses algorithms to identify new, unknown viruses by examining their behavior and characteristics, rather than relying solely on known virus definitions.
Quarantine:
- Isolates suspicious files to prevent them from causing harm while allowing the user to decide whether to delete or restore them.
System Cleanup:
- Removes malware and repairs any damage caused by infections.
Firewall:
- Monitors and controls incoming and outgoing network traffic to prevent unauthorized access and protect against network-based threats.
Email Protection:
- Scans incoming and outgoing emails for malicious attachments or links to prevent phishing attacks and malware distribution.
Popular Antivirus Programs
Norton Antivirus:
- Known for its comprehensive protection and additional features like a password manager and VPN.
McAfee Antivirus:
- Offers robust security features and performance optimization tools.
Kaspersky Antivirus:
- Provides high detection rates and advanced features like parental controls and secure online transactions.
Bitdefender Antivirus:
- Known for its high performance, low impact on system resources, and multi-layered protection.
Avast Antivirus:
- Offers a free version with basic protection and a premium version with advanced features like ransomware protection.
ESET NOD32 Antivirus:
- Focuses on fast performance and advanced threat detection with minimal impact on system speed.
Trend Micro Antivirus:
- Known for strong web protection and effective anti-phishing tools.
Windows Defender:
- Built into Windows operating systems, providing essential protection without the need for additional software.
Best Practices for Using Antivirus Software
- Keep the antivirus software updated: Regular updates ensure the program can protect against the latest threats.
- Run regular scans: Schedule routine scans to check for any potential threats.
- Enable real-time protection: Ensure that real-time scanning is active to catch threats as they arise.
- Be cautious with emails and downloads: Avoid opening suspicious emails or downloading files from untrusted sources.
- Backup important data: Regular backups can help recover data in case of an infection that affects file integrity.