Network Security

Network Security

1. Passive attacks are where someone monitors data travelling on a network and intercepts sensitive information that they find.

   • The best defence is data encryption.
     • Encryption is when data is translated into a code. Only someone with the correct key can access it.
   • They use software such as packet sniffers

2. Active attacks are when someone attacks a network using malware.

   • The best defence is to use a firewall.
     • Firewalls examine all data entering or leaving a network and block any potential threats.
   • Malware is malicious software that is installed on someones device without their knowledge or consent
     • Typical actions of malware
       • Deleting or modifying files
       • Scareware
       • Ransomware
       • Spyware
       • Rootkits - they alter permissions
       • Opening backdoors in someone's security that can be used for attacks.
     • Ways malware can access your device
       • Viruses attach themselves to files and are activated when the files are opened.
         • Anti-virus software can be used.
       • Worms are like viruses but they spread very quickly as they self-replicate
       • Trojans are malware disguised as legitimate software but they don't replicate themselves and users install them and don't realise their hidden purpose.

3. Insider attacks are when someone within an organisation exploits their network access.

4. Brute force attacks use automated software to produce password combinations.

   • Using strong passwords and locking accounts will prevent this

5. Denial of service attacks are when a hacker tries to stop users from accessing part of a network or website.

   • They often involve flooding the network with useless traffic.
     • This will make the network extremely slow

6. People are often the weak points in secure systems.

   • Social engineering is a way of getting information by influencing people.
     • It can take place over the telephone with someone persuading the person to give information.
     • Phishing is when emails are sent claiming to be from a well know company.
       • Phishing emails are sent to thousands of people.
       • You can use anti-phishing software.

7. SQL injections give criminals easy access to insecure data.

   • Networks that use databases are most vulnerable.
   • SQL means structured query language
   • SQL means it can be easy to get past a firewall if the SQL code is insecure.

8. What will a good network policy do?

   • Regularly test the network for problems
   • Use passwords
   • Enforce user access levels
   • Encrypt sensitive data
   • Install anti-malware and firewall software

9. Penetration testing is when organisations simulate attacks.

   • Identifies possible weaknesses

10. Network forensics are investigations to find the cause of an attack on a network.

    • For this to work organisations must have a packet capture system so that the packets can be analysed.

11. Passwords prevent unauthorised users and they must be long and not guessable.

12. User access levels control which part of a network different users can access.

    • Business managers will have higher access levels and may have write access to files others can only read.
      • User access levels limit the risk of insider attaks