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📘 09-02: Common Attacks

Network Systems

Module 09: Network Risk Management

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📌 Denial of Service

Attack Description
DoS Overwhelm a system so it's unavailable
DDoS DoS from many distributed sources (a botnet) — harder to block

📌 On-Path & Spoofing

Attack Description
MITM / on-path Secretly intercept/relay traffic between two parties
ARP spoofing/poisoning Map victim/gateway IP to attacker's MAC to intercept LAN traffic
Spoofing Forge source identity (IP, MAC, email sender)
DNS poisoning Corrupt DNS answers to redirect users

📌 Social Engineering

Attacks that target people, not machines:

Attack Description
Phishing Deceptive email/message to steal credentials or deliver malware
Spear phishing Targeted phishing at a specific person
Pretexting Invented scenario to extract info
Tailgating Follow someone through a secure door

Best defense: user awareness training.


📌 Malware Types

Type Behavior
Virus Needs a host file + user action to spread
Worm Self-replicates across networks, no user action
Trojan Disguised as legitimate software
Ransomware Encrypts data for extortion (harms availability)
Rootkit Hides deep in the OS
Logic bomb Triggers on a condition/date

A zero-day exploits a flaw before a patch exists.


Tip

Key idea — Know DoS/DDoS, MITM/ARP spoofing, phishing/social engineering, and malware types (virus vs. worm vs. trojan vs. ransomware). A zero-day has no patch yet.

See also: Security Concepts, Switch & Port Hardening