1.6 system security

1.6 system security

1. forms of attack

   • Malware
     • includes viruses, worms and trojan horses
       • worms
         • replicate itself in order to spread across a network
           • in order to do this it exploits vulnerabilities in a network
       • torjan horse
         • designed to access a computer by misleading the user of its intent
     • malicious software is designed to cause damage to a network or computer system
       • it attaches itself to files and programs on a computer system
   • phishing
     • designed to acquire sensitive information
     • commonly sent through email
     • telephone phishing
       • direct phone calls that pretend to be an official service
   • brute force
     • trial and error
       • can be used for gaining access to password-based entry systems
     • consists of an attacker entering possible passwords and phrases until one is correct
   • data interception and theft
     • packets that travel over networks can be intercepted
       • if packets are encrypted a key will be needed
     • packets reassembled by using a signature
   • SQL detection
   • social engineering
     • relies on human interaction
     • involves tricking users into breaking normal security procedures
   • DDOS
     • overloading a website with unwanted traffic
     • uses a number of computers over a network of infected machines which send requests to a website which would bring it offline

2. preventing attacks

   • penetration testing
     • tests conducted in a controlled envirmoent
   • network forensics
     • involves the examination of data sent across a network
       • packet sniffing
         • helps a user understand what is being sent across the network all the time
           • packet sniffing without written permission is a breach of the law
   • network policies
     • outline rules for network access
     • acceptable use policy (AUP)
   • anti malware software
     • aims to prevent malware from entering the system
   • firewalls
     • software that performs as a barrier
       • not 100% effective
         • can be held on a server or a stand alone computer
   • passwords
   • encryption
     • data is translated into code
     • julius ceasr
       • the key tells how many places along the alphabet the real letter is
   • user access levels
     • allows a system administrator to set up a hierarchy of users
     • lower level users = limited access

3. threats posed to networks

   • poor network policy
     • can expose a network to many threats
     • most networks restrict users to what they can and cant do