Week 3: Computer Security

Question 1

What is a hacker and describe the types

Answer 1

Hackers gain access to systems in ways unintended by it’s owner;

White hat hackers: Security professionals brought in by contract to test a system’s security.
Grey hat hackers: gain access without any malicious activity, may or may not make companies aware of the vulnerabilities in the code
Black hat hacker: People gaining access without permission. This may be for personal or organisational profit, as well as for activism or civil disobedience. Data will be stolen or altered.

Question 2

Broadly describe the types of Malwares

Answer 2

malicious softwares include;
Virus: self replicating
Trojan horse: pretends to be something else
Worm: spreads from computer to computer
Zombie: controls your computer remotely without your knowledge
Key logger: logs the keys you press
Rootkit: Hides it’s presence by gaining root access to a system, like an administrator, may require new os installation to remove it.
BIOS rootkit: same as rootkit but it’s on the actual motherboard

Question 3

What is Hashing

Answer 3

Hashing is a mathematical process known as a one-way or trap-door function since they cannot be reversed to find the original password. It is an algorithm which takes data of any size and maps it to a fixed-size hash value.

Question 4

Describe the ways to crack passwords

Answer 4

Brute force attack: Going through passwords one character at a time, trying every combination of characters.

Dictionary attack: testing commonly used passwords and words.

Rainbow table attack:
Uses pre-computed encrypted passwords already computed with a hashing algorithm. Using large amounts of computing power (e.g. botnets) will reduce the time these attacks take.