Chapter 2: Network Security Threats¶

Overview¶

Chapter 2 introduces the wide range of threats that target network security. These threats may come from malicious attackers, accidental user actions, technical failures, or physical and environmental disasters. Understanding these threats is essential for protecting networked systems.

Attacker Motivations¶

Attackers target networks for several reasons:

Financial gain
Political or ideological goals
Espionage
Revenge or personal challenge

Knowing attacker motivation helps organizations anticipate potential attack methods.

The Five Phases of Hacking¶

Most cyberattacks follow a structured process:

Reconnaissance - Collecting information about the target - Examples: social media, public records, DNS lookups
Scanning - Identifying open ports and vulnerabilities - Examples: port scanners, vulnerability scanners
Enumeration - Gathering detailed system information - Examples: user accounts, network resources
Attacking - Exploiting discovered vulnerabilities - Examples: malware installation, password attacks
Post-Attack Activities - Maintaining access and hiding activity - Examples: backdoors, data exfiltration

Common Network Security Threats¶

Malware¶

Malware is software designed to harm or exploit systems.

Viruses
Worms
Trojans
Ransomware
Spyware

Hardware and Environmental Threats¶

Hardware failures
Power outages or surges
Natural disasters such as fires or floods

Insider Threats¶

Users with authorized access
May be intentional or accidental
Often difficult to detect

Advanced Network Attacks¶

Session Hijacking¶

Takes control of an active user session
Common on unsecured connections

Spoofing¶

Falsifying identity to appear trusted
Examples include IP, email, and DNS spoofing

Man-in-the-Middle (MitM) Attacks¶

Intercepts communication between two parties
Can steal or alter data in transit

Denial-of-Service Attacks¶

Denial-of-Service (DoS)¶

Overloads a system with traffic
Originates from a single source

Distributed Denial-of-Service (DDoS)¶

Uses multiple compromised systems
More difficult to mitigate than DoS attacks

Defenses and Mitigation Strategies¶

Encryption to protect data
User training and awareness
Access control and least privilege
Monitoring and intrusion detection
Regular patching and updates

Key Takeaways¶

Cyberattacks typically follow predictable phases
Social engineering is a major security risk
Malware and advanced attacks continue to evolve
Effective security relies on both technical and human defenses