9 (a) Explain what is meant by a denial of service attack. (b) Name and describe two other potential security threats when using the Internet. Security threat 1 Description Security threat 2 Description

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2016). The mark or mark type is shown in brackets.

1. [2] (a) Any two from:
2. a large number of requests are sent to the network/server all at once
3. designed to flood a network/server with useless traffic/requests
4. the network/server will come to a halt/stop trying to deal with all the traffic/requests
5. prevents users from gaining access to a website/server
6. [4] (b) 1 mark for each security threat and 1 mark for matching description
7. Security threat: Viruses
8. Description: software that replicates; causes loss/corruption of data // computer may "crash"/run slow
9. Security threat: Hacking/cracking
10. Description: illegal/ unauthorised access to a system/data
11. Security threat: Phishing
12. Description: a link/attachment sends user to fake website (where personal data may be obtained)
13. Security threat: Pharming
14. Description: malicious code installed on user's hard drive / computer; user is redirected to a fake website (where personal data may be obtained)
15. Security threat: Spyware/key logger
16. Description: send/relay key strokes to a third party