Cyber Crime & Cyber Security – Comprehensive Exam Notes

Introduction to Cyber Security

• Cyber Security (a.k.a. Information Security, IT Security)

  • Practice of safeguarding computers, servers, mobile devices, networks, and data from malicious attacks.

  • Became critical due to:

  • Explosive growth of the Internet and smartphones.

  • Proliferation of online banking, shopping, e-payments.

  • Escalating threats: hacking, phishing, data breaches, identity theft, ransomware, etc.

• Core Goals (CIA Triad):

  • Confidentiality – keep data private / restricted.

  • Integrity – ensure data is complete and unaltered.

  • Availability – make systems, services, and data usable on-demand.

Cybercrime

• Definition: Any criminal activity using or targeting computers, networks, or digital devices.

• Two broad classes:

  • Attacks ON computers (e.g., malware infection, hacking a server).

  • Attacks USING computers (e.g., online fraud, cyber-bullying campaigns).

• Major Types & Examples:

  • Hacking – unauthorised system entry.

  • Phishing – deceptive e-mails or sites to steal credentials/PII.

  • Ransomware – files encrypted; $\text{victim} \xrightarrow{\text{pay ransom}} \text{key}$.

  • Cyberstalking – persistent online harassment or threats.

  • Identity Theft – impersonation using stolen digital identity.

  • Online Fraud – counterfeit shopping sites, fake lotteries, investment scams.

• Why Cybercrime is So Widespread:

  • Massive smartphone & Internet adoption.

  • Limited digital literacy; social-engineering works.

  • Weak passwords, lax security hygiene.

  • Heavy public-Wi-Fi usage.

  • Remote-work boom (post-COVID) widens attack surface.

Information Security (InfoSec)

• Objective: Protect information against unauthorised access, disclosure, modification, or destruction.

• Information Categories & Examples:

  • Personal: name, address, Aadhaar, passwords.

  • Financial: bank a/c, credit-card numbers.

  • Business: trade secrets, plans, R&D data.

  • Government: classified defence or diplomatic docs.

• Key Threats:

  • Hacking, phishing, malware, insider abuse/leakage.

Categories of Cybercriminals

• Hackers – breach systems to explore or steal.

• Crackers – maliciously damage or deface.

• Script Kiddies – use pre-made exploits/tools, limited skill.

• Insiders – disgruntled or careless employees, contractors.

• Cyber Terrorists – ideological, political, or religious motives.

• State-Sponsored Hackers – espionage, sabotage on behalf of governments.

E-mail Spoofing

• Forges “From” field so message seems from trusted sender.

• Used for phishing, malware delivery, financial scams, impersonation.

• Detection Tips:

  • Spelling/grammar anomalies.

  • Inspect full header / domain.

  • Hover to reveal real link.

  • Question urgent cash / credential requests.

Spamming

• Sending unsolicited, irrelevant, or bulk messages via e-mail, SMS, social media, comments, robocalls.

• Common Characteristics:

  • Generic salutation: “Dear Customer”.

  • Fantastic offers: “Win $₹10\,\text{lakh}$ NOW!”.

  • High urgency: “Act today or lose account!”.

  • Suspicious attachments (.exe, .zip) or unknown sender.

Cyber Defamation

• Publishing false, harmful, or offensive statements online (posts, tweets, blogs, e-mails).

• Impacts: reputation damage, mental anguish, career/relationship loss, potential civil/criminal liability for defamer.

Internet Time Theft

• Employees’ non-work usage of corporate IT resources during paid hours.

• Activities: social media scrolling, video streaming, gaming, personal chat, online shopping.

• Considered cyber-offense because:

  • Squanders company bandwidth/time.

  • Lowers productivity, may open security holes.

  • Violates HR/IT policy.

Salami Attack

• Repeated theft of minute amounts ($\approx ₹0.01$) that are individually unnoticed but cumulatively large.

• Process:

  1. Program skims fractional remainders from huge volume of transactions.

  2. Credited silently to attacker’s account.

  3. Continues until detected (often years). Classic in banking/finance.

Data Diddling

• Altering data at input stage so system processes manipulated values, producing fraudulent outputs.

• Often insider-driven; attacker reverts data afterward to hide traces.

Cyber Forgery

• Creation/alteration of digital docs, records, or signatures to deceive.

• Variants: fake PDFs, tampered databases, forged e-mails, counterfeit e-signatures.

• Consequences: monetary loss, reputational harm, legal penalties, broken trust in data integrity.

Web Jacking

• Attacker seizes control of a website/webpage by phishing admin credentials or exploiting vulnerabilities.

• Typical Kill-Chain:

  1. Clone admin login page.

  2. Lure owner to fake URL.

  3. Capture creds ⇒ hijack real site.

• Prevention: enforce HTTPS, strong/rotated passwords, 2-Factor Authentication, routine patching.

Computer Sabotage

• Intentional destruction, disruption, or degradation of computer assets.

• Techniques: deploying malware/ransomware, wiping disks, corrupting backups, DoS attacks, physical tampering.

• Targets: gov’t infrastructure, corporate data centers, critical utilities (power, water, transport).

Password Sniffing

• Intercepting network packets to harvest plaintext passwords.

• Effective where:

  • Protocols lack encryption (HTTP, FTP, Telnet).

  • Networks are open/public Wi-Fi.

• Mitigations:

  • Use HTTPS, SSH, VPN.

  • Enforce password hashing & encryption in transit.

  • MFA.

Credit Card Frauds

• Unauthorised use of card info to shop or withdraw.

• Attack Flavours:

  • Carding – test & use stolen card numbers in bulk.

  • Phishing – mimic bank / payment gateway.

  • Skimming – hidden hardware on ATM/POS reads mag-stripe & PIN.

  • Data-Breach Theft – mass exfil of retailer/bank databases.

• Defences:

  • Never disclose OTP/CVV over call/e-mail.

  • Ensure “https://” and padlock before paying.

  • SMS/e-mail transaction alerts; audit statements.

  • Virtual cards, 2FA, spending limits.

Vulnerability

• A flaw/weakness exploitable by adversaries.

• Categories:

  • Hardware (e.g., Meltdown/Spectre CPU bugs).

  • Software (unpatched OS, buffer overflows).

  • Network (open ports, weak Wi-Fi encryption).

  • Human (poor awareness, social engineering, insider threats).

• Management Lifecycle:

  • Discover ⇒ Assess ⇒ Prioritise ⇒ Patch ⇒ Verify.

  • Use scanners, IDS/IPS, awareness training.

Cyber Threats & Harmful Acts

• Threat = potential danger; exploit → incident.

• Frequent Threat Vectors:

  • Malware (virus, worm, Trojan), ransomware.

  • Phishing, spear-phishing, vishing, smishing.

  • Spyware/keyloggers.

  • DDoS.

  • Social-engineering, BEC (Business E-mail Compromise).

• Harmful Outcomes:

  • Data theft/leak.

  • System destruction or crypto-locking.

  • Service outages, revenue loss.

  • Fraudulent transactions, brand damage.

CIA Triad – Deep Dive & Illustrations

Confidentiality

• Ensures only authorised parties may view data.

• Threats: unauthorised access, weak encryption, insider leaks.

• Measures: strong encryption (AES, RSA), VPN tunnelling, least-privilege access, DLP, classification & labelling.

• Simple encryption depiction:

  • Alice encrypts “Hello Bob” with secret key ⇒ ciphertext $6EB69570\;08E03CE4$.

  • Bob decrypts using same key ⇒ original message.

Integrity

• Guarantees data accuracy, consistency, and trustworthiness.

• Threats: tampering, malware, ransomware, accidental errors.

• Controls: hashes (SHA-256), digital signatures, checksums, version control, WORM backups.

• Hash demo (small changes ⇒ huge digest shift):

  • Original sentence “The red fox jumps over the blue dog” ⇒ digest $\text{DFCD 3454 … 2D17}$.

  • Alter one character “over → ouer” ⇒ digest $0086 46BB … 3ABC$.

  • Shows avalanche effect.

Availability

• Systems/data ready when needed.

• Threats: DoS/DDoS, hardware failure, sabotage, natural disasters.

• Protections: redundancy, load-balancing, WAF, rate-limiting, backups, UPS/generators, incident response.

• Classic DDoS diagram: attacker → handlers → botnet zombies → flood victim, exhausting resources.

Cyber Security Policy

• Formal rule-set describing how an organisation secures assets & complies with law/regulations.

• Objectives:

  • Standardise security posture & expectations.

  • Prevent unauthorised access/misuse.

  • Ensure adherence to GDPR, HIPAA, PCI-DSS, ISO $27001$, etc.

  • Elevate staff awareness & accountability.

Domains within a Cyber Security Policy

• Access Control Policy – who/what/when/where/how data is accessed (RBAC, ABAC).

• Acceptable Use Policy (AUP) – proper vs forbidden use of IT resources.

• Incident Response (IR) Policy – detection, containment, eradication, recovery, post-mortem.

• Network Security Policy – configuration of firewalls, IDS/IPS, VPN, segmentation.

• Data Protection & Privacy Policy – classification, encryption, retention, GDPR consent.

• Remote Access Policy – secure VPN, MFA, device posture check.

• BYOD Policy – enrolment, MDM, containerisation, wipe on-loss, minimum OS version.

These bullet-point notes preserve every concept, definition, example, rationale, risk, and mitigation mentioned in the transcript while adding context, real-world relevance, and exam-ready structure.