1. Technical Implementation: Security Risks
National 4
viruses, worms, trojans
hacking
National 5
phishing, keylogging (hardware and software), virus, online fraud, identity theft
anti-virus software
good password settings
Biometrics
firewalls
Security Precautions

2. What is a secure computer system?
A computer system is secure if it:
cannot be accessed by unauthorised person
not infected by malicious software
malware is software that
disrupts the operation of a computer system
allows illegal access to a computer system

3. Why are these security risks a problem?
We use computers for everything:
private messages
online shopping – card details on your computer
organisations store your personal and private details on computers

4. Virus copies (replicates) itself to infect other programs or computers
needs human activity to spread – file must be run or opened in order to infect a computer system
viruses attach themselves to other programs to ensure this happens

5. Worm does not need to attach itself to another program
transmits copies of itself to other computers using networks
some worms only spread and do nothing else – they disrupt by consuming network bandwidth and storage space

6. Trojan
a program that appears safe but has a virus or worm hidden inside
disguises itself as another type of file, even as an anti-virus program!
e.g. download a game, program or picture and when you run the file the virus or worm infects your computer

7. When does a virus strike?
malware may not affect your computer system straight away
may wait for
a specific date before activating – time bomb
a specific action to take place – logic bomb
why wait?
more systems can be affected before discovery

8. How viruses spread
sharing infected optical discs (CD or DVD) or flash memory between computers
creating optical discs or using flash memory on an infected computer
attachments
across networks
downloads

9. Virus effects (what a virus can do)
corrupted or lost files and data
displaying unwanted messages
unusual images or sounds played
rebooting/restarting unexpectedly
generation of spam s
denial of service attacks

10. Hacking
hacking is gaining unauthorised access to a computer system – usually illegal
a crime under the Computer Misuse Act
Black Hat Hacker who uses their skills illegally – often for money, respect or for a political cause
White Hat Hacker who uses their skills to break into computer systems for legal purposes such as testing security of computer systems

11. Keylogging
recording every key that is pressed without the user knowing
may be software or hardware
used illegally by criminals to get sensitive data like account numbers and PINs
used legally to help test programs, monitor employee’s productivity

12. Phishing an attempt to get you to give away personal information
criminals pretend to be a well known company or bank
how: , text message, telephone calls, social engineering

14. What was wrong with that email?
no username
‘account will terminated’ – an attempt to get you to do it asap
bad grammar and missing full stops
click here – cannot see hyperlink address
Go to the official website by typing it into the address bar or doing a search for it. Avoid clicking on links through .

15. Online fraud
online fraud (internet fraud) is the use of internet services to defraud people of money or to carry out identity theft
lots of different types including:
paying for goods which never arrive
supplying bank or personal details to a stranger e.g. ‘I am a prince from <country>, please send your bank account details so I can send you £50 million …’

16. Anti-virus Software
a software application which protects against infection by viruses and other malware
detects and removes viruses before they spread further or do damage
needs a connection to the internet to download updates to help protect against new viruses

17. Anti-virus Software
always running so has an impact on system performance
checking:
files from the internet
programs and data you are using
optical discs and flash memory
attachments

18. Passwords a user identity and password allow
controlled access to computer systems
passwords should be strong

19. Passwords strong password: at least 8 characters long
contain at least:
1 upper-case (A-Z) AND 1 lower-case character (a-z)
1 number (0-9)
1 special character etc)
no more than three repeating characters (111) or ordered characters (567)

20. Passwords
to prevent a keylogger stealing passwords, some websites now ask you to select random characters from your password
you don’t type so the keylogger cannot record it

21. Biometrics
biometrics use your physical characteristics or behaviour to identify you to a computer
physical characteristics:
finger prints
palm prints
face recognition
eye scans – retina or iris

22. Biometrics behavioural characteristics: how you walk voice recognition
signature

23. Biometrics Advantages
more secure than a password or card which can be lost or stolen
difficult to forge some biometrics (e.g. fingerprints)

24. Biometrics Disadvantages physical danger
e.g. cut hand/finger off
you cannot get new data if stolen or tampered with

25. Firewalls
a system to prevent unauthorised access to or from a private network
rules and conditions specify what information is blocked and what is allowed to pass through

26. Firewalls hardware firewall software firewall
can be built into a router
has no effect on computer performance
protects the whole network
software firewall
always running so may impact computer performance
if on your PC protects only that PC