Unit 1: Introduction to Security

Social engineering means tricking people into giving away information, opening a harmful file or clicking a bad link. It often arrives by email, text or social media. Watch for intimidation (threats if you don't obey) and urgency (pressure to act right now). Falling for it can hand an attacker your personal details, a one-time login code, or malware that steals data saved in your browser.

In an online password attack, someone tries common, patterned or stolen passwords on a real login page. Warning signs are many failed logins in a short time, logins at odd hours and logins from unknown devices. Attackers build guess lists from personal details like pets' names and birthdays, so use long, random, unique passwords or passphrases (a password manager helps) and turn on multifactor authentication (MFA).

Low-skilled attackers use tools bought online, while high-skilled ones build their own tools and find unknown flaws called zero-days. On Wi-Fi, an attacker may set up an evil twin (a fake network with a look-alike name), jam the signal so no one can connect (a denial of service), or go war driving to find networks that reach outside a building. Protect yourself by checking the network name exactly and relying on encryption like HTTPS. A VPN hides your traffic from the local network, but the VPN provider can still see it.

Attackers use AI to clone a person's voice or face for fake calls and video chats, and to write polished phishing in any language. They also coax sensitive data out of chatbots, plant false information that ends up in AI training data, and use AI to speed up research and malware writing. You can fight back with a secret word or phrase shared with family, MFA, keeping personal data out of AI tools, and checking AI answers against reliable non-AI sources.

Networks log millions of events a day, far more than people can read. Defenders train AI tools to sort likely attacks from harmless activity, alert the security team and even take quick corrective action. AI can also review firewall rules, scan code for vulnerabilities and suggest detection rules, but a knowledgeable person should always check its suggestions before they're used.