Describe how the database can be recovered from a system failure
What is a computer virus?
A computer virus is a program designed to damage other programs or causes irregular behaviour in a computer system.
State the symptoms of a computer virus
A virus is a specific category of malware. Describe three other different categories of malware.
Trojan (horse); a program which misleads the user into thinking it is another
piece of software which, when run, executes another program;
Spyware; a program which records data such as usernames and passwords on
a host system and forwards the information to a third party;
Adware; code embedded or attached to program files which will persistently
show adverts (that attempt to generate revenue);
Worm; code which will run autonomously and replicates itself on a host system;
Ransomware; a program that encrypts a user’s data to make it unreadable until
they pay for the key;
Remote Access Tool (RAT); allows access to control and monitor a computer
from a remote network location;
Rootkit; malware that has managed to gain ‘root’ admin privileges;
Bots/Zombies; a program installed on a computer that performs a job for the
remote owner of the bot/zombie such as sending spam or sending web requests
to perform a DOS or attack a computer system;
Scareware; malware that tells you something is wrong with your system in an
attempt to get you to make a purchase;
Keylogger; a program that monitors/records a user’s keystrokes in order to steal
passwords/confidential details
Give three features of a data protection act.
Explain why a firewall improves network security.
State three advantages of biometric authentication
What is meant by RAID technology?
RAID (Redundant Array of Independent Disks) technology refers to a method of combining multiple physical disk drives into a logical unit to improve performance, data availability, and data redundancy. RAID technology is commonly used in storage systems to provide fault tolerance, data protection, and increased storage performance.
The primary purpose of RAID is to create a more reliable and robust storage solution by spreading data across multiple drives and implementing various data redundancy techniques. This helps to mitigate the risk of data loss and system downtime in case of drive failures.
There are different levels or configurations of RAID, each offering different features and trade-offs. The most commonly used RAID levels are:
RAID 0 (Striping): Data is split evenly across multiple drives, resulting in increased performance as data can be accessed from multiple drives simultaneously. However, there is no redundancy, so if one drive fails, data loss can occur.
RAID 1 (Mirroring): Data is duplicated or mirrored across two drives, providing redundancy. If one drive fails, the other drive can still function and serve the data. RAID 1 offers data protection but does not offer increased performance.
RAID 5 (Striping with Parity): Data and parity information are striped across multiple drives, providing both increased performance and fault tolerance. Parity information allows for the recovery of data in case of a single drive failure. RAID 5 requires a minimum of three drives.
RAID 10 (Combination of Mirroring and Striping): RAID 10 combines elements of RAID 1 and RAID 0. It involves mirroring data across two sets of drives and then striping the mirrored sets for increased performance and fault tolerance. RAID 10 provides high levels of data redundancy and performance but requires a minimum of four drives.
State the symptoms of a computer virus
Slow Performance: If your computer suddenly becomes significantly slower than usual, taking longer to boot up, open applications, or respond to commands, it could be a sign of a virus. Viruses can consume system resources, resulting in decreased performance. Frequent Crashes: If your computer frequently crashes, freezes, or experiences sudden system reboots without any apparent reason, it could be due to a virus. Some viruses can interfere with system stability, leading to unexpected crashes or instability. Unusual Pop-ups or Ads: If you start noticing an excessive number of pop-ups, advertisements, or banners appearing on your computer screen, especially when you're not browsing the internet, it might be an indication of adware or malware infection. Unwanted Modifications: Viruses can modify system settings or configurations without your consent. If you observe changes in your default browser homepage, new toolbars appearing, unfamiliar icons on the desktop, or altered settings, it could be a sign of a virus. Unusual Network Activity: If you notice excessive network traffic, unusual data transfers, or a sudden increase in data usage without any known reason, it could be an indication of a virus or malware actively communicating with external servers. Missing or Modified Files: Viruses can delete, encrypt, or modify files on your computer. If you find missing files or encounter unexpected changes in file sizes, names, or extensions, it could be a result of a virus infection. Disabled Security Software: Some viruses attempt to disable or circumvent antivirus or security software to avoid detection. If you notice that your antivirus program or firewall is deactivated, modified, or unable to update, it could be due to a virus compromising your security software. Unexpected Email or Message Activity: Viruses can use infected computers to send spam emails or messages to contacts in your address book without your knowledge. If your friends or colleagues report receiving suspicious or unexpected emails or messages from you, it could be a sign of a virus.
Describe how the denial of service strategy works to compromise the security of networks.
Jane has noticed the following problems with her computer (2mks)
State three possible causes of these problems and how they can be solved (3mks)
There could be several possible causes for the issues Jane is experiencing with her computer keyboard, including:
1. Software Issues
- Cause: Outdated or corrupt system files, drivers, or operating system.
- Solution:
- Ensure the operating system and drivers are up-to-date.
- Run a system file checker to repair any corrupted system files (e.g., on Windows, run "sfc /scannow" from the Command Prompt).
- Consider reinstalling the operating system if issues persist.
2. Hardware Issues:
- Cause: Physical damage or malfunction in the keyboard hardware.
- Solution:
- Check for physical damage or debris under the keys and clean the keyboard if necessary.
- If cleaning doesn't help, consider replacing the keyboard with a new one.
3. Resource Overload:
- Cause: The computer may be running too many background processes or lacking sufficient hardware resources.
- Solution:
- Close unnecessary background applications and processes to free up system resources.
- Consider upgrading the computer's RAM, CPU, or storage if it's outdated and unable to handle current software demands.
- Use task manager or activity monitor to identify and terminate resource-intensive processes.
4. Malware or Viruses:
- Cause: Malicious software can slow down a computer, cause hanging, and delay startup.
- Solution:
- Perform a full system scan using reputable antivirus or anti-malware software to remove any threats.
- Ensure that the operating system's security patches are up-to-date.
5. Disk Fragmentation:
- Cause: Fragmented files can slow down the loading of applications and overall system performance.
- Solution:
- Run a disk defragmentation tool (e.g., Windows' built-in tool) to optimize file storage on the hard drive.
- Consider upgrading to a solid-state drive (SSD) for faster application loading times.
6. Insufficient Storage:
- Cause: If the hard drive is nearly full, it can cause slow performance.
- Solution:
- Free up space by deleting unnecessary files and programs.
- Consider upgrading to a larger capacity hard drive or SSD if storage space remains an issue.
7. Background Processes and Startup Items:
- Cause: Too many unnecessary programs running in the background or starting up with the computer.
- Solution:
- Disable or remove unnecessary startup items and background processes to improve startup time.
- Use the Task Manager or System Preferences (on macOS) to manage startup items.
It's important to diagnose the specific cause of the issues Jane is facing by troubleshooting each potential problem one by one. In some cases, a combination of these solutions may be necessary to fully resolve the problems with her computer keyboard.
There are security concerns associated with cloud storage.
(a) State one way in which providers of cloud storage could prevent security breaches by their own employees
(b) Explain why data on networks is encrypted
(a) One from:
(b) To prevent unauthorised access (1) so that data remains confidential (1) by making it unintelligible (1) because it is scrambled (1)
Define social engineering
State two reasons for carrying out software updates
The act of soliciting for sensitive information from unsuspecting users. According to study.com, it is the use of various forms of technology to deceive people into divulging private information:study.com
Eavesdropping refers to tapping or listening into communacation channels to get information. According to study.com, it is defined the unauthorized interception of a conversation, communication or digital transmission in real time study.com
Peter has installed internet on his home computer in order to use it for browsing. State three ways in which he would prevent viruses from infecting his computer. (3 marks)
Describe what is meant by ‘RAID 10’.
What are the likely causes of data and program loss in a computer (2 marks)
How many hard disks are required to implement RAID 10?