Topic 9 Part 6: Computer Security and Ethics

Unauthorized access involves an attacker attempting to break into a system. A common method is a brute-force attack, where the attacker tries multiple passwords. For example, an attacker might try '12345', then 'ABCDE', and eventually 'Ellis' to gain access to Bob's system via SSH.

Brute-force attacks are just one way to get unauthorized access. Other methods include phishing or social engineering. Once access is gained, an attacker might install a rootkit or a backdoor to ensure future access.

To detect unauthorized access, a security officer can install an Intrusion Detection System (IDS). To prevent it, a network manager might use a firewall, a whitelist (allowing access from known sources), or a blacklist (preventing access from certain sources). A specific tool to protect against SSH brute-force attacks is Fail2ban.

Beyond unauthorized access, other computer security concerns include stolen IT equipment and improper disposal of old equipment. Awareness is also highlighted as an important aspect of computer security.