Flashcards
Network Security and Threats
Cards in this deck (11)
- 1FirewallSecurity checkpoint
Prevents unauthorised Internet access between two networks
- Network 1: Internal, trusted
- Network 2: External, untrusted
Consists of two NICs on a single computer - one connected to each network
Analyses all data packets passing between the two networks, accepting or rejecting them according to predefined rules - 2Packet filtering (Static filtering)Controls network access according to admin rules and policies
Source and destination IPs are examined and compared to a whitelist - those on the whitelist are accepted, those not on the whitelist are rejected
Packets can also be blocked based on protocols - certain protocols use certain ports so the packets using that port will be rejected - 3Proxy serversIntercepts all packets entering and leaving the network
Allows privacy and anonymity by hiding the true network address of the source from the recipient
May maintain a cache of commonly visited websites to speed up access and reduce traffic - webpages are added to the cache as they are requested and removed if they are not used frequently - 4EncryptionUsed to scramble messages transferred via the Internet
Specific algorithms are often used - symmetric for message transmission, with key exchange and digital signature algorithms to ensure it can occur - 5MalwareSoftware designed to cause inconvenience, loss or damage to computer systems and/or their contents
May be used for the creator's personal benefit or as a weapon - 6VirusesMalware
Contains malicious code to perform damaging functions (e.g. data theft, data disruption, etc.)
Rely on human actions to spread and replicate (e.g. opening a file, running a program, etc.) - 7WormsMalware - subtype of viruses
Uses software vulnerabilities to spread and infect other machines without human input
Can also inject malicious code - 8TrojansMalware
Manifests as a seemingly useful or harmless file or program to install
When installed, the payload is released
Often the payload is a backdoor for the creatr to exploit
Can be used to harvest data or slave the computer to a botnet (e.g. for a DDoS attack) - 9VulnerabilitiesCan be software bugs but also human error
People can:
- Switch of firewalls
- Fail to use virus protection
Admin can:
- Fail to prevent access to vulnerable areas
Cracks in software (data passing) - 10Weakest point in softwarePeople
- Passwords are often written down or easily guessed
- People are vulnerable to social engineering - 11Threat protection- Ensure code is of a high quality
- Do not allow a buffer overflow (common attack for injecting malicious code)
- Take caution in emails (easy target for social engineering)
- Regularly update OS and antivirus software
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- Description
- A level OCR A level Computer Science (Topic 5 - Networks and Web Technologies) Flashcards on Network Security and Threats, created by James Norman on 04/02/2020.
- Created by
- James Norman
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