You are currently viewing List the Type of Computer Viruses. Explain each in detail
List the Type of Computer Viruses. Explain each in detail

List the Type of Computer Viruses. Explain each in detail

File Infectious Virus:

File infector viruses are one of the most common types of computer viruses. They infect executable files (such as .exe or .dll files) by embedding their malicious code in these files. When an infected file is executed, the virus becomes active and spreads to other executable files on the system, allowing the infection to persist.

How they work: File infector viruses typically attach or append their malicious code to a target file, modifying its structure in a way that allows the virus to execute when the file is opened or executed. Once activated, the virus can perform various malicious actions, such as stealing data, corrupting files, or facilitating unauthorized access to the infected system.

Examples: Notable examples of file infector viruses include the CIH virus (also known as Chernobyl), which gained widespread attention in 1998 for its ability to overwrite the BIOS and disable infected systems, and the Sasser worm, which Exploited vulnerabilities in Windows systems. Spread rapidly throughout the network in 2004.

Mitigation: To protect against file infectious viruses, users should exercise caution when downloading or executing files from unknown or untrusted sources. Additionally, installing and regularly updating antivirus software can help detect and remove file infector viruses from infected systems.

Macro Virus:

Macro viruses are malicious programs that exploit macros, automated sequences of commands within document files (such as Microsoft Word or Excel documents). These viruses infect documents by embedding their malicious macro code, which is executed when the infected document is opened with a compatible application.

How they work: Macro viruses typically infect document files (e.g., .doc, .xls) by embedding malicious macro code in them. When a user opens an infected document and enables macros, the virus’s code is executed, allowing it to perform various malicious actions, such as spreading to other documents, corrupting data, or stealing sensitive information. .

Example: One of the most notorious macro viruses is the Melissa virus, which spread in 1999 via infected Word documents attached to emails. Melissa infected thousands of systems worldwide and caused widespread disruption by overloading email servers with infected messages.

Mitigation: To reduce the risk of macro viruses, users should use caution when opening email attachments or downloading documents from unknown sources. Disabling macros by default in Office applications and configuring security settings to block macros from untrusted sources can also help prevent infection.

Boot Sector Virus:

Boot sector viruses infect the master boot record (MBR) or the boot sector of a storage device (such as a hard drive or USB drive). These viruses become active when the infected system boots, allowing them to take control of the boot process and execute their malicious code before the operating system loads.

How they work: Boot sector viruses typically replace or modify legitimate boot code stored in the MBR or boot sector of a storage device with their own malicious code. When the infected system boots, the virus’s code is executed, causing it to load before the operating system and gain control of the system’s boot process.

Example: Stoned virus, one of the early boot sector viruses discovered in the 1980s, infected the MBR of floppy disks and hard drives, causing a message when the system booted (“Your PC is now stoned!”). Was displayed. Another notable example is the Michelangelo virus, which attracted media attention in 1992 due to its ability to overwrite data on infected systems on March 6 (the birthday of Renaissance artist Michelangelo).

Mitigation: To protect against boot sector viruses, users should be cautious when booting from an external storage device or inserting removable media into their system. Installing and regularly updating antivirus software can help detect and remove boot sector viruses from infected systems.

Polymorphic Virus:

Polymorphic virus is a sophisticated type of malware that can change its appearance or signature every time it infects a new file or system. This ability to mutate makes polymorphic viruses challenging to detect and mitigate using traditional antivirus or signature-based detection methods.

How they work: Polymorphic viruses use encryption or obfuscation techniques to modify their code every time they infect a new file or system. By changing their appearance or signature, polymorphic viruses can avoid detection by antivirus software and increase their chances of successfully infecting target systems.

Example: The Storm worm, which emerged in 2007, was a polymorphic virus that spread via email attachments and malicious links. The virus’s ability to rapidly mutate made it difficult for antivirus vendors to develop effective signatures for detection, allowing it to infect millions of systems worldwide.

Mitigation: To protect against polymorphic viruses, organizations should deploy advanced threat detection solutions that use heuristic analysis, behavior-based detection, or machine learning algorithms to identify and block malicious code. Additionally, implementing strict access controls, network segmentation, and endpoint security measures can help prevent and mitigate the spread of polymorphic viruses within the network.

Resident Virus:

Resident viruses are a type of malware that embed themselves in the system’s memory, allowing them to remain active and execute their malicious code even after the initial infection process is complete. This persistence makes resident viruses challenging to detect and remove from infected systems.

How they work: Resident viruses usually load themselves into the system’s memory during the boot process or when an infected file is executed. Once loaded into memory, the virus remains active and can intercept system calls, manipulate data, or infect other files when they are accessed or executed.

Example: The CIH virus, also known as Chernobyl, was a resident virus that infected executable files and the system’s BIOS, causing it to overwrite the BIOS and disable the infected system. Another example is the Jerusalem virus, which infects executable files and memory, causing system crashes and data loss.

Mitigation: To reduce the risk of resident viruses, users should regularly update their antivirus software and perform full system scans to detect and remove malicious code from the infected system’s memory. Additionally, implementing security best practices, such as practicing safe browsing habits, avoiding downloading files from unknown sources, and applying security patches promptly, can help prevent resident virus infections.

In conclusion, computer viruses come in different forms, each with their own unique characteristics, spread methods, and effects on infected systems. Understanding the different types of computer viruses and their behavior is essential to developing effective mitigation strategies and protecting against cyber threats. By being vigilant, practicing good cybersecurity hygiene, and implementing strong security measures, individuals and organizations can reduce the risk of virus infection and protect their digital assets and infrastructure against malicious attacks.

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