Back to: Jss3 Computer Science – ICT (BST)

How to Prevent Computer Viruses

Ensure that your computer’s operating system is always kept up-to-date by using Windows update or software update on a MAC. Avoid using file-sharing programs to download games, TV shows, and other files. Instead, make use of ClamXAV and Windows Defender or other security software on your personal computer. It’s essential not to click on advertisements when using the internet and never give your password to anyone else. Refrain from responding to spam messages in your inbox. It’s important to educate yourself on viruses and how they invade computer systems. Always perform virus scans on your computer to maintain a healthy system.

Sources of Viruses

1. Infected diskettes: This occurs when users share secondary storage devices without confirming their status, for example, flash drives, etc.
2. Internet download: Illegally downloading music or movies on the internet.
3. Illegal duplication of software: When users purchase and install illegal software on their computer system.
4. Failure to follow safe browsing conditions by users.
5. E-mails: Opening of corrupted programs sent into the inbox.

Virus Warning Signs

Viruses work in various ways and cause havoc on computer systems until all their functions grind to a halt. Therefore, it is necessary to detect a computer virus infestation to combat the damage it can cause. Running routine virus scans is one way to protect your computer from malicious attacks.

Common symptoms of Computer Viruses

1. Slowing down response time: The speed at which the computer operates suddenly decreases. It becomes unusually slow because some virus programmes have executed tasks in the background. If the computer is suddenly more sluggish than usual, freezes or even crashes, there is a high possibility that a virus could be the cause.
2. An influx of Email Messages Not Sent By User: Computer viruses use email spamming to spread and infect other computers. Some malware programmes hijack emails and start sending infected messages to contacts without your knowledge. So, one way to tell if your computer is infected with a computer virus is if there are sent email messages that you did not initiate yourself. This can be hard to discover, especially if you rarely check the sent messages folder in your email. However, always be on the lookout and detect any unusual sent email messages.
3. Constant Alerts and Error Messages on the Desktop: When surfing the internet, it is common to have false pop-up advertisements; once they begin to appear on the system it is certain that the computer has been infected by a virus. These alerts come up as error messages; they warn of viruses running in the background and recommend the purchase of anti-spyware that will solve the problem. Do not buy the recommended spyware programmes because they are used to steal financial information.
4. Programs and Functions that no Longer Work: When trying to open an application or system utility that refuses to boot or launch for some reason, it could be as a result of a virus attack. Malicious programmes usually delete essential files that applications require to function properly. When that happens, the affected programmes or operating system utilities fail to launch or do not work as expected. Sometimes, this can be caused by software or hardware malfunction. To be sure that a virus attack is behind programme malfunction, troubleshoot the problem, but if this does not resolve the issue, there is a high chance that your computer is infected.
5. Unknown Toolbars on Your Browser: If a browser has new toolbars that were not installed by the user, this is a sign that you visited an infected website. Virus authors like to spread malware, spyware, and other malicious software through web browser adware. It is important to remove unknown toolbars as soon as they are noticed. These unknown toolbars can save your internet history, passwords and steal other personal information as you surf the web.
7. New programmes are not installing: This means that the computer is having difficulty installing new software or programmes. The installation process may not be completing successfully, or there may be an error message that is preventing the programme from being installed.
8. Computer has trouble booting Windows: This refers to a problem that occurs when the computer is unable to start up or load the Windows operating system properly. This could be due to a hardware issue or a software problem.
9. Internet access being blocked: When the user is unable to access the internet, it may be due to a firewall or security setting on the computer, or it could be due to a problem with the internet service provider.
10. Desktop appearance or screen saver and other visual settings are changed unexpectedly: This refers to a situation where the visual settings on the computer, such as the desktop background or screen saver, have been changed without the user’s knowledge or consent. This could be due to a virus or malware infection.
11. When the user is unable to open files or folders: This means that the user is having difficulty accessing or opening files or folders on the computer. This could be due to a problem with the file or folder itself, or it could be due to a software or hardware issue.
12. When files or folders are deleted unexpectedly: This refers to a situation where files or folders on the computer have been deleted without the user’s knowledge or consent. This could be due to a virus or malware infection, or it could be due to accidental deletion.
13. When the computer is unable to print documents and the hard disk runs out of space.: This means that the computer is having difficulty printing documents, and there may also be a problem with the amount of available storage space on the hard disk. This could be due to a hardware issue with the printer, or it could be due to a software problem with the computer.
14. When infected files begin to replicate themselves: This refers to a situation where a virus or malware infection on the computer is causing files to be copied and spread to other parts of the system. This can lead to a serious security breach and can cause damage to the computer’s files and operating system.

Virus Detection (Antivirus)

Antivirus is a type of software designed to protect computer systems from malicious software, also known as malware. It works by detecting and removing viruses, spyware, and other harmful programs that can cause damage to a computer system or compromise its security.

Antivirus software is an essential tool for anyone who uses a computer, particularly those who access the internet regularly. It is important to keep the software up to date, as new threats emerge all the time, and the software needs to be able to detect and defend against them.

The way antivirus software works is by scanning a computer system for any suspicious or malicious files. It can detect and remove viruses from files, emails, and other data that may have been infected. It can also protect against phishing attacks and other forms of malware, such as Trojan horses and worms.

Types of Antivirus

1. Signature-Based Antivirus: This is the most basic type of antivirus software that identifies malware based on its signature, or specific code pattern. Signature-based antivirus software is effective against known threats but is less effective against new or unknown threats.
2. Behaviour-Based Antivirus: Behaviour-based antivirus software identifies malware based on its behaviour, such as attempts to modify files or registry settings. This type of software is more effective against new or unknown threats but can generate false positives.
3. Heuristic Antivirus: Heuristic antivirus software uses advanced algorithms to identify malware based on suspicious behaviour, such as self-replication or attempts to modify system files. This type of software is more effective against new or unknown threats but can also generate false positives.
4. Sandbox Antivirus: Sandbox antivirus software creates a virtual environment to run potentially malicious code, isolating it from the main system to prevent it from causing damage. This type of software is effective in identifying and stopping new or unknown threats.
5. Cloud-Based Antivirus: Cloud-based antivirus software uses a network of servers to scan files and identify potential threats. This type of software is effective in identifying new or unknown threats and is less resource-intensive on the local system.
6. Firewall Antivirus: Firewall antivirus software provides protection by blocking unauthorized access to a system or network. It can prevent malware from communicating with remote servers or downloading additional files.
7. Rootkit Antivirus: Rootkit antivirus software is designed to detect and remove rootkits, which are malicious programs that allow attackers to gain unauthorized access to a system or network. Rootkit antivirus software can identify and remove rootkits, preventing further damage.
8. Online Scanner: Online scanner antivirus software allows users to scan their systems for malware without downloading or installing software. This type of software is useful for quick scans but may not provide comprehensive protection.
9. Endpoint Antivirus: Endpoint antivirus software is designed to protect endpoint devices, such as laptops, desktops, and mobile devices. It provides protection against a range of threats and can be managed centrally from a single console.
10. Mobile Antivirus: Mobile antivirus software is designed to protect mobile devices against malware and other cyber threats. It can scan apps and files for potential threats and provide protection against phishing attacks and other mobile-specific threats.