Computer Security
Unit 9 Summary - Part 1
Files' data is valuable because
-
Creating the files takes time and money.
You don't want your data to be lost or corrupted.
-
It's helpful for your work/business.
Example: customers' phone numbers or their bank details. If this data is gone/corrupted, you can't collect your payment or you can't have business with them.
-
It has private information.
Example: it has your phone number, address, and credit card information. You don't want other people to have access to it.
Data Loss:
The data no longer exists in your storage because it's deleted by mistake, or your USB flash drive is gone.
Removable data:
Data can be copied to a removable storage (such as a USB flash drive, portable harddisk, or CD/DVD).
If this storage falls in the wrong, it might give unauthorised access to private data or might get malware from another computer.
Some ways to protect your data:
-
Use Encryption, Anti-virus, and Firewalls.
-
Members and staff should be trained to securely use the company's computers.
What is Unauthorized Access?
Access rights:
-
No access:
You can't connect to the system at all.
-
Read only:
You can have a look at the data, but you can't make changes.
-
Read/Write:
You can make changes to the all or some of the data.
-
Admin:
You can make changes to the whole system.
Example: You can reset the passwords, change settings & defaults, remove software, etc.
Don't set a wrong access right on a wrong person.
Unauthorised Access:
-
Privacy:
Someone who doesn't have permission has seen or copied your data.
-
Integrity:
Someone who doesn't have permission makes changes to the data.
This is sometimes called hacking.
Cyber Crime!
Computer crime:
-
Piracy:
Copying music, games, movies, etc without permission or without paying.
-
Identity theft:
Stealing someone's personal details and pretending to be that person.
-
Malware:
Creating and distributing malware.
-
Hacking/Cyber Attack:
Gaining unauthorised access to computers by finding out passwords or by bypassing security systems.
-
Damage or steal someone's computer hardware or storage.
PIRACY!
Why Indonesian movies, Music, & Software don't thrive in Indonesia?
Making music, movies, & software is expensive, because the company has to pay the employees.
When people can download for free without paying the company, the company doesn't have income, and it's bankrupt soon after.
PIRACY also impacts the employees greatly:
Many artists, singers, musicians, music producers can't have their dream jobs because almost all record labels in Indonesia (true story about 100 of them) are bankrupt.
The employees need to pay the bills, so they're forced to live in the field that they don't love at all.
Without piracy, Indonesian companies might produce movies or music as great as other countries.
Out country might be as rich as the USA or South Korea if our government is serious about punishing piracy acts.
Malware
Malware
is Malicious Software to harm your computer.
You get malware by downloading a file from the internet, by using an infected storage, or by visiting a fake website.
Types of Malware:
-
Computer Virus
is an executable file containing a set of commands to do these things:
-
copies itself to your computer files, and copies itself to other computers.
-
change data in the files.
-
delete files, or wipe the entire storage.
-
alter/modify your computer settings (example: lock your computer)
-
make your computer carry out actions (example: sending fake emails)
-
Trojan:
is hidden in a harmless file, (examples: pirated video games, pirated movies, etc.)
When you install the video game or download pirated movies that have trojan in them, your computer is infected.
Trojan Horse is actually a story from Ancient Greek Myth where the enemy gave a gift in a shape of a big horse. When the king brought the gift into their safe space, suddenly enemies were
coming out of the big horse's body and killed a lot of people in the kingdom.
-
Spyware:
is recording everything you type or everything you do on your computer. It's used to steal your ID and password when you type them.
-
Adware:
is installing advertisement software to pop-up adverts on your screen. Sometimes you cannot close the window, or whatever you type on your browser, it directs you to a different website.
Avoid Malware:
-
Only download software and other content from legal & official websites.
-
Don't open attachments or click on links of a suspicious email.
-
Keep your software up to date.
Anti-Virus software:
Install an anti virus to:
-
check all new files and emails for malware,
-
scan your computer to find hidden malware,
-
remove malware from your computer,
-
warn you about possible danger, such as risky website.
Security patch:
is to fix vulnerabilities on computer system.
Hackers always evolve their ways of finding computers' weaknesses.
Always keep software up to date to apply security patch in order to deal with the latest threats.
New viruses are made every day, and has newer trick to avoid anti-virus software. Keep your anti-virus up-to-date often to keep up with new threats.
Oxford AQA IGCSE 2019
03.3.
Describe three security measures that could be taken to protect a computer network. [6 marks]
__________________________________________________________________________________
Alternative Answers:
-
Virus Checker:
Scans files to look for malicious code; Should be updated regularly; Regular updating protects against new viruses; Can quarantine / delete malware/suspicious files;
-
Firewall:
Analyses/scans network traffic; Can block traffic from/to suspicious hosts/ computers/addresses; Can block traffic from/to certain ports/certain types of traffic; // Blocks access to network, if no other marks awarded
-
Login system / Authentication / Password / Biometric:
User has to enter (username and) password; User provides biometric data (accept examples); Login details matched to a database of users; Enforce use of strong passwords; Strong password consists of mix of letters/characters/symbols; Strong passwords are harder to hack/crack/guess; Passwords changed regularly;
-
MAC address filtering:
Each hardware device has unique hardware address; A database of allowed hardware/MAC addresses is kept/whitelist; To connect to a network a device must have an address on the database/whitelist;
-
Encryption:
Use WPA/WPA2; Data is stored/transmitted as ciphertext (A. in coded form); Unauthorised users cannot understand (A. read) data // only authorised users can understand it; Key needed to decrypt/read the data;
-
Unauthorised external storage devices:
USB ports on a computer are disabled; Storage devices connected to them cannot be accessed // flash drives cannot be used;
-
Access rights:
Users are associated with certain privileges; These might control files that can be accessed/run // level of Internet access // ability to create/delete files // ability to change settings;
-
CAPTCHA:
Users have to type in some distorted text // recognise images for a set of images; A. other reasonable tasks Humans can do this but it is a difficult task for computer programs / bots;
-
(Automatic) software updates:
Operating system / software configured to download updates from the Internet; Hackers look for security vulnerabilities in software; Updates can patch security vulnerabilities; Automatic updates are better than manual updates as there is no reliance on people;
-
Maintain Log:
Keep a log/record of actions undertaken; Can be analysed to identify unauthorised activities // facilitates early responses; May deter hackers if they know actions are being tracked;;
-
Use Wired Connections:
Wired connections are more secure; Harder to intercept data as not transmitted in air; Must tap into cable/device to steal data;
-
Backup Data:
Make a separate copy of data; Can be restored if the original data is lost/changed; Store away from original; Test that backups work;
-
Penetration Testing:
Get someone to try to break the security measures / to try to hack the network; This can inform changes to security; White-hat has some knowledge of how network configured; Black-hat has no knowledge of how network configured;
Oxford AQA IGCSE Mock Paper
08.1.
Table 1 lists some terms that are related to cyber security and malware. Each term is identified by a letter.
Table 1
Table 2 lists definitions of some cyber security and malware terms.
Complete Table 2 by writing into it the Letter (A-F) from Table 1 of the term to which the definition corresponds.
Do not use the same letter more than once. [3 marks] Table 2
